Special Print – Will Not Be Kept Up To Date

Specification No. P1TF108

GE Issue No. S5
Date 23
Aviation Page 1 of January 8, 2021
CAGE Code 07482
General Electric Company Supersedes P1TF108-S4
Cincinnati, OH 45215

GE PROPRIETARY INFORMATION
The information contained in this document is GE proprietary information
and is disclosed in confidence. It is the property of GE and shall not be
used, disclosed to others or reproduced without the express written consent
of GE, including, but without limitation, it is not to be used in the
creation, manufacture, development, or derivation of any repairs,
modifications, spare parts, designs, or configuration changes or to obtain
FAA or any other government or regulatory approval to do so. If consent is
given for reproduction in whole or in part, this notice and the notice set
forth on each page of this document shall appear in any such reproduction
in whole or in part.
This technical data is considered ITAR and/or EAR controlled pursuant to 22
CFR Part 120/130 and 15 CFR Parts 730-774, respectively. Transfer of this
data by any means to a Non-US Person, whether in the United States or
abroad, without the proper U.S. Government authorization (e.g., License,
exemption, NLR) is strictly prohibited.

SPECIFICATION

INTERPRETATION OF DRAWING

1. SCOPE

1.1 Scope. This specification provides general information for the

interpretation of drawings including definition and explanation of terms,
symbols, and drafting practices.

1.1.1 Classification. This specification contains the following

class[es]. Unless otherwise specified, the requirements herein apply to all
classes.

CLASS A: ASME Y14.5M-1994 Dimensioning and Tolerancing

CLASS B: ASME Y14.5-2009 Dimensioning and Tolerancing

Distribution Approved by:

10A
 Evendale
 Lynn
 P1TF108-S5

1.2 Definitions. The following definitions shall apply as used in this

specification and on drawings invoking this specification and specifications
invoking thereon:

Alternate Process Completion - Completion of a part to eliminate a

nonconformance by performance of a process different than that which was
initially used to produce the nonconforming characteristic [e.g., welding
of castings].

Customer and Partner Interfaces – Feature designations that have no

effect on the manufacture of the item containing them, but which serve as
flags to warn that decisions on future revisions, possible field repairs,
disposition of non-conformances, ect. must weight the effects on the
installation of the item into the customer application, or the assembly
of the item with a partner’s associated item.

Enhanced Manufacturing Controlled Part (EMCP) – Those commercial and

military static parts that fall into the general category of casings
containing compressor discharge pressure and non-redundant engine mount
components non-integral to the engine frames or casings. The control of
surface anomalies is ensured frames or casings. The control of surface
anomalies is ensured by P1TF9 and P1TF101 and requires the processes that
could impact the life of the part be documented by Engineering in a
manufacturing plan.

Life-Controlled Parts – Those commercial and military parts that fall

into the general category of disks, spools, main engine shafts, disk-like
seals, impellers, blisks and combustion cases. They include rotating
parts that are life tracked in service and may be considered fracture
critical in accordance with ENSIP (Engine Structural Integrity Program)
requirements. Consistent material properties are ensured by: (1) Vendor
substantiation cut-up specimens, (2) A defined periodic cut-up plan, and
(3) A defined test ring cut-up plan. Also the control of surface
anomalies is ensured by P1TF111 and requires the processes that could
impact the life of the part be documented by Engineering in a
manufacturing plan.

Process Completion – Completion of a part to eliminate a nonconformance

by repetition of the process which was initially used to produce the
nonconformance characteristic (e.g., rewelding, rebrazing).

Purchaser – The procuring activity of GE Aircraft Engines that issued the

procurement document invoking this specification. When this specification
is invoked by an U.S. Government Purchasing Activity (or such activity’s
designee), the Purchaser shall mean such activity or designee as the case
may be.

2
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

Statistical Control (In Control) – The condition describing a process

where all variations of observed samples can be attributed to a
consistent system of chance causes.

Statistical Process Control (SPC) – The application of statistical

techniques to process performance data to investigate, quantify, locate
and separate inherent, random variability from assignable causes so
appropriate action can be taken.

Supplier – The Supplier duly contracted by the Purchaser to perform the

manufacture of the components. (The term Supplier may also refer to an
organizational unit of GE).

2. APPLICABLE DOCUMENTS

2.1 Issues of Documents. The following documents form a part of this

specification to the extent specified herein. Unless otherwise indicated,
the latest revision/year designation shall apply.

AMERICAN SOCIETY OF MECHANICAL ENGINEERS

ASME B46.1 Surface Texture (Surface Roughness,

Waviness, and Lay)

ASME Y14.5M-1994 Dimensioning and Tolerancing

ASME Y14.36M Surface Texture Symbols

ASME Y14.38 Abbreviations and Acronyms

ASME Y14.5-2009 Dimensioning and Tolerancing

AMERICAN SOCIETY FOR TESTING AND MATERIALS

IEEE/ASTM SI 10 Standard for Use of the International

System of Units (SI): The Modern Metric
System

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS

IEEE 200 Reference Designations for Electric and

Electronics Parts and Equipment

IEEE-STD-315 Graphic Symbols for Electrical and

Electronics Diagrams

3
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

2.2 Order of Precedence. In the event of conflict in requirements, the

order of precedence shall be as follows:

1st The Drawing

2nd Other Specifications Referenced on the Drawing
3rd This Specification
4th All Specifications Referenced Herein

2.2.1 Other Specifications. For other specifications referenced on the

drawing, the latest revision shall apply unless the drawing specifies a
specific revision.

3. MATERIALS AND PROCESSES

3.1 Finished Part Material Condition. Finished part properties are

designated by the material or part specification supplemented where necessary
with a drawing note or notes. The condition and form of the starting
material need not conform to those of the finished part.

3.1.1 Heat Treatable Materials. In the case of materials which develop

properties through heat treatment (e.g., alloy steels, age hardenable
superalloys) finished part properties are generally designated by the
material or part specification supplemented or modified as required by the
drawing. In cases where the drawing changes the specification heat
treatment, but does not change part property requirements, the material or
part specification properties shall apply.

3.1.2 Non Heat Treatable Materials. In the case of materials which do

not develop their properties through heat treatment (e.g., plain austenitic
stainless steel, solid solution strengthened superalloys, etc.) finished part
properties are greatly influenced by the properties of the starting material,
by fabrication of the part and by some thermal processes. Unless the drawing
includes modifications to property requirements, the finished part properties
shall be those resulting from the processing specified.

3.2 Nontraditional Material Removal. The use of nontraditional material

removal i.e., chemical, electrochemical, mechanical, and thermal as a method
of material removal requires the approval by the Purchaser prior to initial
manufacture. Each application of the process(es) on each design (different
part or assembly number) requires approval. If the Purchaser’s drawing
specifically allows such method, this constitutes Purchaser approval.

3.2.1 Application. The requirements of 3.2 applies only to components

whose drawings specify “Vendor Substantiation Required” and is included in
this Specification to emphasize the need for approval prior to initial
manufacture. After initial manufacture, changes shall be approved in
accordance with the applicable Vendor Substantiation Requirements. Requests
for approval prior to initial manufacture shall be processed the same as
requests for approval of a change.

4
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

3.3 Material Release Note. The note CLASS B MATERIAL RELEASE on a

drawing, in some instances coupled with a GE Quality Control Requirements
Specification, applies to Suppliers only and denotes that the certificate of
test received from the Material Supplier may be the sole basis for release of
material providing the certificate is complete enough to establish that the
material meets the requirements of the applicable specifications. If the
certificate of test is not complete, test must then be performed or
additional data obtained from the Material Supplier until it is established
that the material meets the applicable specification and material release
requirements imposed on the Material Supplier.

3.4 Benching. The removal of burrs and surface flaws such as nicks,
scratches and dents with operations usually performed on a work bench where
either the work piece, tool or both are hand held. Benching is not
considered a machining operation. This includes metal removal with hand held
tools such as files or abrasive cloth or hand held power tools such as dental
type cutters, abrasive disks, belts or wheels. The use of benching shall not
cause the part to exceed dimensional limits or specification requirements.

3.5 Chemical Composition. Material specifications prescribe the

chemical elements that make up the composition of the material. Limits for
the alloying elements are usually established as a toleranced percentage and
the listed impurities as a maximum percentage. The basics element from which
the alloy is made is specified as the remainder. The basic element is
assured to be present in an amount approximately equal to the difference
between one hundred percent and the sum of the alloying elements and the
listed impurities. The specification limits do not preclude the presence of
other unspecified elements, i.e., trace or residual elements, in minute
quantities. When necessary to limit the quantity of trace elements, criteria
will be specified on the drawing or in a referenced specification. An
analysis need not be made for each element of the periodic table not
mentioned in the material specification.

4. VENDOR SUBSTANTIATION

4.1 Vendor Substantiation. Drawings of certain parts and assemblies

have a note stating that Vendor Substantiation is required. This note
applies to GEAE manufacturing operations as well as other GE and non-GE
sources that manufacture items to the drawing. Special testing or inspection
of these items will be required prior to Qualification/Certification. After
Qualification/Certification of an item, no changes may be made in the
processes or sources, identified as significant, used for the original item
except as authorized by the Purchaser. Detail requirements will be conveyed
through the Purchase Order. Note that the terms “Vendor Substantiation” and
“Source Substantiation” as used by GEAE are synonymous.

5
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

5. GENERAL REQUIREMENTS

5.1 Visual Indications. All parts are subject to inspection for visual
indications. Visual indications are surface discontinuities which can be
observed without magnification or aid of an nondestructive evaluation (NDE)
process, that may indicate the presence of surface flaws (see para. 9.2).
For those parts that require NDE, visual indications have the same limits of
size and spacing as the drawing-specified NDE criteria.

5.3 Electrical Symbols and Designations. Electrical symbols and

designations are as specified in IEEE-STD-315 and IEEE 200.

5.4 “Otherwise Same As” Spare Part Drawings. When a spare part drawing
references another drawing as “otherwise same as” in order to complete the
part definition the full requirements of both drawings shall apply. The
spare part drawing defines the differences, so requirements specified thereon
take precedence over similar requirements on the referenced “otherwise same
as” drawing. Duplication of information between drawings does not signify
any degree of importance.

6. DIMENSIONING AND TOLERANCING

CLASS A: Dimensioning and tolerancing is based on recognized industry

practice as established by the American Society of Mechanical Engineers
Standard ASME Y14.5M-1994. The requirements in this section provide
interpretations not covered in or are different than ASME Y14.5M-1994.

CLASS B: Dimensioning and tolerancing is based on recognized industry

practice as established by the American Society of Mechanical Engineers
Standard ASME Y14.5-2009. The requirements in this section provide
interpretations not covered in or are different than ASME Y14.5-2009.

6.1 Units of Measure. When toleranced dimensions are called out only in
US Customary units (inches), but are converted to and measured in SI units
(millimeter), rounding shall be per IEEE/ASTM SI 10, although the absolute
limits of the US Customary unit shall be met.

6.1.1 Dual Dimension. When toleranced dimensions are specified in both

the US Customary unit (inches) and the International System of Metric units,
the Metric units conform to IEEE/ASTM SI 10.

6.2 Finished Part Dimensions. Dimensions appearing on drawings and in

specifications define the finished item and shall be met when the part is
free from external forces and after all processing such as heat treating and
machining. The dimensions include the effect of subsequent shrinkage or
growth with time resulting from heat-treating. This effect is subject to
verification at any time.

6
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

6.3 Requirements at Drawing Level. Dimensions and other requirements on

the drawing of an item are mandatory only at the drawing level where they are
invoked unless otherwise specified. Subsequent processing of the item to the
requirements of a higher-level drawing may result in changes to the lower
level item that could not reasonably be prevented at the higher level. These
changes can occur as the result of forces introduced by processes such as
machining, welding, heat-treating, bolting and press fitting. However,
where, in the Purchaser’s opinion, such changes are the result of improper
processing or careless handling, the items are subject to rejection.

6.4 Effect of Surface Coatings. Unless a specific coating requirement

states whether dimensions to a coated surface shall be met before or after
coating, the following applies:

(a) For inorganic coatings such as platings, ceramic coatings,

chromates, and oxides, the dimensions including surface texture
apply after coating.

(b) For organic coating such as paints and lubricants, the dimensions
including surface texture apply before coating.

6.5 Chamfer. Chamfers are dimensioned by a basic angle and toleranced

length. The chamfer dimension is the linear measurement along the length of
the part and not along the slope of the chamfer. See Figure 1.

6.6 Intersection of Surfaces. Dimensions shown to edges that are

rounded (round edge), or broken (break edge) apply to the intersection of the
extended surfaces. See Figure 2.

7
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

Figure 1 – Chamfer

8
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

Figure 2 – Intersection of Surfaces

6.7 Radius. A radius dimension requires a smooth curve that is tangent

to adjacent surfaces and is within the specified limits with no portion of
the curve less than the minimum radius. A true circular arc is not required.
See Figure 3. When a radius is specified only as R (without the dimensional
value) between parallel surfaces, the tolerance zone for the radius is
established by two concentric semicircles equal in diameter to the minimum
and maximum width limit specified on the drawing between the parallel
surfaces.

9
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

Figure 3 – Radius

10
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

6.8 Round Edge. This term, which applies to outside edges only,
requires that the resulting contour be (a) a radius within the specified
limits, or (b) convex or flat or a combination of both blended into the
adjoining surfaces with a radius not less than the minimum value and meeting
the contour as shown on Figure 4.

Figure 4 – Rounded Edge

11
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

7. DRAWING DEFINITIONS AND INTERPRETATIONS

7.1 Backlash. Unless otherwise specified when backlash requirements are

specified for bevel gear assemblies, the value specified is the “normal”
backlash. The normal backlash between bevel gears is measured at the heal of
the gear at the approximate pitchline in a direction perpendicular (normal)
to the tooth surface. The measurement of both normal and tangential backlash
is obtained by holding the pinion solidly against rotation and by then moving
the gear back and forth. Tangential backlash is also measured at a radius
equal to the radius of the pitch diameter. The measurement is taken along a
line tangential to the pitch diameter. If it is more convenient to measure
tangential backlash, the specified normal backlash limits shall be modified
by dividing the normal value by the produce of the cosine of the spiral angle
times the cosine of the pressure angle. The tangential readings will then be
compared to those modified limits.

7.2 Continuous Feature. CLASS A: The term "continuous feature"

indicates where a group of two or more features of size are to be treated
geometrically as a single feature of size.

7.3 Double Drill. A re-drilled hole whose center line axis is not
coincident to the original hole and where the resulting geometry is not
acceptable. Some geometry resulting from re-drilling may be acceptable;
therefore, a drawing that prohibits double drilling holes does not prohibit
the process of re-drilling. Acceptability criteria for geometry of re-
drilled holes are determined by Design Engineering.

7.4 Key Features. Characteristics of the engineering drawing whose

control is essential for the success of the process and to meet design
intent. Key features are for process control use and should not be confused
with classification of characteristics.

7.5 Nontraditional Material Removal Method. Any material removal method

where tool or workpiece contact is nonexistent or minimal is considered
nontraditional, e.g., chemical, electrochemical, mechanical, or thermal.

7.6 Significant Surfaces. When the drawing specified plating on a

“significant surface”, it means that all portions of the surface shall be
plated to the thickness specified except the areas at inside intersecting
surfaces which lie between the contact points of a .75 diameter ball. No
base metal exposure is permitted in this area. See Figure 5.

12
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

Figure 5 – Significant Surfaces

Figure 7 – KC Symbol Applied to Linear Dimension

7.7 Surface Texture (Roughness, Waviness, and Lay). Symbols are in

accordance with American Society of Mechanical Engineers Standard ASME
Y14.36M, requirements and interpretations are in accordance with American
Society of Mechanical Engineers Standard ASME B46.1. Measurements may be
made by instrument or by sight and feel comparison to commercially available
gages. In cases of dispute, however, the instrument method of measure
described in the American Society of Mechanical Engineers Standard takes
precedence over sight and feel comparison.

(a) For instrumentation purposes, all surface roughness measurements

are arithmetical average deviations from the centerline and shall
be made with a roughness-width cut-off .030 unless otherwise
specified.

(b) Unless surface texture is designated on radii or other changes in

contour, the finish must be at least equivalent to the coarser
surface texture required on the adjoining surfaces.

(c) When commercial stock (i.e., sheet metal, bar, rod, tubing, etc.)
is used with no external surface texture indicated on the drawing,

13
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

commonly accepted mill finished for the material specification

will apply.

(d) The effect of flaws is not included in the roughness height

requirements. See Paragraph 5.1 and 9.2.

(e) When a surface texture symbol includes a lay specification, that

lay characteristic shall be present on the finished surface. If
subsequent processing obliterates the lay characteristic, it shall
be restored within drawing limits.

(f) An Average Surface Roughness, designated AVG or AVG RA,

is the arithmetic mean of a minimum of three individual surface
roughness (Ra) instrument readings.

(g) When an Average Surface Roughness is specified on flowpath

surfaces of Airfoils, Blades or Vanes, and when the flowpath
surface exhibits a visually discernable lay pattern, the surface
roughness (Ra) instrument reading shall be measured from the
leading edge to the trailing edge or from the trailing edge to the
leading edge.

(h) The following applies to Ra measurements only on flowpath surfaces

of Turbine airfoils (see below for examples). Ra may be measured
with the following parameters:

(1) Waviness cut-off length: 0.010

(2) Stroke length: 0.100
(3) Filter: Gaussian preferred; 2RC is an acceptable alternate
(4) Short cut-off length, if available, shall be set to none.

Features that are flowpath surfaces include blade and vane

airfoils, nozzle band surfaces, blade platform, and tip shroud
surfaces that create the gas path. Angel wings that are smooth and
continuous with the gas path are also included. Transition areas
may be included.

7.8 Tabulated Data. A dash (-) appearing in a column or row of

tabulated data has the same meaning as ‘not applicable’.

7.9 Tabulated Features. Partial views that depict configuration

differences from the corresponding areas on the principal views. Tabulated
features are blocked in and numbered sequentially, i.e., Tabulated Feature
No. 1, Tabulated Feature No. 2, etc. Tabulated feature views are invoked in
the tabulation block that lists the differences between the several items
defined on the drawing.

14
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

8. QUALITY PROVISIONS

8.1 Classification of Characteristics. Classification of

characteristics provides a common basis for indicating, during all phases of
production, maintenance and operation, the relative hazard created if the
characteristic were discrepant. The assigned degree of classification does
not in any way imply that the specified limits on all requirements do not
have to be met in the manufacture and inspection of the product. These
classifications are a prerequisite for statistical sampling.

8.1.1 Definitions. Characteristics are those dimensional, visual,

functional, mechanical, or material features or properties which describe and
constitute the design of an item, which can be measured, observed, or
identified in order to determine conformance to design requirements. Since
classifications are assigned by considering variation of only one
characteristic at a time, they are not necessarily valid if two or more
characteristics are discrepant simultaneously.

8.1.2 Symbols. “C/C” applied near the engineer’s approval signature

means that the drawing or specification has been classified for
characteristics. The symbols and definitions for classification are as
follows:

(a) CRITICAL. ⊕ Those characteristics of an item which, if

nonconforming, may result in hazardous or unsafe conditions for
personnel using, maintaining or depending on the unit-of-product;
or which may prevent or seriously affect the satisfactory operation
or functioning of the unit of product.

(b) MAJOR. Those characteristics of an item which, other than

critical, which if nonconforming, nay result in operational or
functional failure of the item, or which materially reduce the
usability, physical or functional interchangeability or durability
of the unit-of-product for its intended purpose.

(c) MINOR. (No Symbol). Those characteristics of an item which, if

nonconforming, do not materially reduce the usability, physical or
functional interchangeability or durability of the unit-of-product,
or are departure from established standards having no significant
bearing on the effective use or operation of the unit-of-product.

8.1.2.1 Documents Without Symbols. It is possible that a document will

have no symbols. Provided the “C/C” is indicated adjacent to the Engineer’s
signature, all characteristics are minor.

8.1.3 Symbol Location. Symbols are placed in close relation to the

characteristic. If the symbol applies to only one dimensional limit or to a
portion of a note, it is placed in relation to the specific limit or the
specific portion of the note enclosed in brackets. When both US Customary
and SI Units are specified on the drawing, i.e., dual dimensioned drawings,

15
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

the classification of characteristics symbol is applicable to both Units

although the symbol(s) is only shown with the US Customary Unit.

8.1.4 Referenced Specifications. Critical and major characteristics in

referenced specifications are indicated by a direct reference on the drawing
or by the applicable symbol in the text of the specification.

8.1.5 Applicability. When a manufacturing process, functional

requirement, or inspection test is classified, the classification applies
only to the inspectable end results.

8.1.6 Threads. When a thread is classified e.g., ( .250-28 UNJF-3A),

the classification symbol applies to the pitch diameter including roundness
and taper and the pitch diameter equivalents of lead and angle errors of
internal and external threads and to the root radius of controlled root
radius threads. The classification of other characteristics of thread form
and size and the relationship between the thread and other machined datums is
minor unless otherwise specified.

8.1.7 U.S. Army Flight Safety Part. Drawings of certain parts and
assemblies contain the following designation: U.S. Army Flight Safety Part.
This designation implies that all characteristics classified as critical on
the drawing or in the specifications included thereon, unless otherwise
specified, are subject to additional safeguards and controls during
manufacture, operation, field repair and maintenance as required in the
contract. Specific requirements for manufacture of these parts are specified
in P1TF94.

8.2 Gaging of Screw Threads. Parts made to drawings or specifications,

which call out Screw Thread Standards for UN, UNJ, UNR, M, and MJ threads,
shall be gaged as follows:

8.2.1 Method of Gaging. Unless the Purchaser specifies a more precise

control (e.g. System 23 instead of 22, or System 22 or 23 instead of 21), the
following gaging systems shall be used for CLASS 3 threads. A more precise
system may be used at the manufacturer’s discretion.

CLASSIFICATION OF THREAD GAGING SYSTEM (METHOD)

CHARACTERISTIC (See 8.1.6) External Threads Internal Threads

Critical ⊕ 23 23

23 22
Major
21 21
Minor (no symbol)

8.2.2 Questionable Threads. The method of gaging does not infer

permission to depart from specified dimensions and tolerances. Where
acceptability of CLASS 3 threads is questionable, System 23 may be used as
the referee procedure.

16
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

8.3 Key Characteristics(KC). Designation of a KC is based on the

characteristics relationship to engine level performance requirements. This
allows engineering to identify key characteristics which require statistical
control. The assessment for identifying KCS are not to be confused with
criteria provided in paragraph 8.1 for the classification of a characteristic
as "critical", "major", or "minor".

8.3.1 KC Definition. A KC is an attribute or feature whose variation has

a significant influence on product fit, performance, service life, or
producibility; which requires specific action for the purpose of controlling
variation.

8.3.2 KC Symbol. A characteristic which is identified as a KC, is

designated on the product definition using the KC symbol as shown on
Figure 7.

8.3.3 KC Symbol Location. A KC symbol is placed in close relation to

the key characteristic. When both US customary and SI units are specified on
the drawing, i.e., dual dimensioned drawings, the KC symbol is applicable to
both units although the symbol is only shown with the US customary unit.

8.3.4 Applicability. When a manufacturing process, functional

requirement, or inspection test is designated as a KC, the classification
applies only to the inspectable end results.

*8.4 Characteristic Numbers (CN). A characteristic number provides a

unique number assignment to a characteristic of an end item that is to be
accounted for during First Article Inspection (FAI).

*8.4.1 CN Definition. A CN identifies those dimensional, visual,

functional, mechanical, and material features or properties that describe and
constitute the engineering definition of the article and can be measured,
inspected, tested, or verified to determine conformance to the engineering
definition.

*8.4.2 CN Symbol. A characteristic is identified with a CN symbol as

shown on Figure 8.

17
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

*Figure 8 – Characteristic Number Symbol – General Application

9. GENERAL INFORMATION

9.1 Purpose. This section provides information of a general or

explanatory nature to assist in the interpretation of the drawing and
specification. It does not contain any requirements.

9.2 Definitions of Terms. The terms pertaining to flaws are defined

below:

BURNISH MARKS - A shiny area resulting from rubbing against another

surface. May contain scratches of no measurable depth.

BURR – The thin edge or roughness left on a processed part.

CHATTER MARKS – A recurring pattern in a machined surface resulting from

vibration between the tool and a machined surface.

CHILL MARKS – Those marks or indications that are the result of a

metallic chill being placed on the surface of a sand casting.

COLD SHUT – Casting flaw that has a folded or wrinkled surface caused
by the meeting of two streams of metal too cold or viscous to mix
properly. Can also be caused by oxide films or dirt on the surface of
the metal streams.

CONTAMINATION – (Foreign Material) Contamination is conditions such as

machined chips, grinding dust, forming materials, loose heat-treat
scale, corrosion, oil, and other foreign material.

18
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

CORROSION – Chemical or electrochemical reaction between a material and

its environment that results in loss of material, accumulation of
deposits and a deterioration of its properties.

CRACK – A separation, fissure, or rupture, usually narrow or tight,

characterized by sharp edges and sharp changes in direction.

CRACK-LIKE – A surface indication that has all the appearances of a

crack but cannot be positively identified as a crack because of the
lack of sub-surface evaluation.

DENT – An impression on the surface of the part, which is shallow,

compared to its minimum surface dimension and has smooth edges and
rounded bottom, such as the imprint of a steel ball.

DISCOLORATION – A noticeable change in color from the adjacent areas of

a surface. The discoloration may be the result of one or more of the
following:

(a) A defect, such as a material flaw

(b) A previous process

(c) Contamination, such as corrosion or dirt

DROSS – The scum that forms on the surface of molten metals largely
because of oxidation but sometimes because of rising of impurities to
the surface.

FIN – A thin projection of metal from the casting, formed either as a

result of cracked refractory or from parting line flash, which was not
removed from the pattern.

FLOW LINE – A rounded, smooth-bottomed linear imperfection caused by

discontinuous flow velocities during wax pattern injection or pouring
of the casting.

FOLD, LAP, SEAM – A flaw caused by the continued plastic working of

overlapping surfaces which because of their condition do not weld
together.

FORMED DEPRESSION – A change in surface level resulting when a tool or

die is used to apply force to a part during a forming process.

HIGH METAL – Metal that has been raised or extruded higher than
surrounding area. It is usually caused by impact processes such as
metal stamping or found at the edges of nicks or dents.
HOT TEAR – A fracture formed in a metal during solidification because
of hindered contraction.

19
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

INCLUSION – Impurities such as oxides, sulfides, and silicates that are

held mechanically within the metal.

MAR – A surface irregularity which is not readily visible but can be

felt by touch.

MICROSHRINKAGE – A spongy condition in a casting usually of significant

depth, which may open onto the surface in the form of a tightly spaced
group or cloud of pinholes which may or may not be interconnected by
fine crack like lines.

MISRUN – A casting not fully formed, resulting from the metal

solidifying before mold is filled.

NICK – A gouged depression with steep sides and “V” impression in the
bottom, such as the imprint made by a sharp object, not interpreted as
a crack or is crack-like.

PARTING LINE – A line on a pattern or casting corresponding to the

separation between adjacent sections of a pattern die or segments of a
sand mold.

PIT – A shallow depression resembling a small crater caused by

corrosion or impingement of foreign particles against the surface.

POROSITY – An isolated, noninterconnected pore or cavity opening to the

surface of a casting. Generally shallow in depth and surrounded by
otherwise sound metal.

POSITIVE – A surface imperfection of plus metal caused by the mold

marking process or wax pattern processing.

SCRATCH – A shallow, narrow furrow in the surface as caused by a sharp

object moving lightly along the surface.

SEGREGATE – A concentration of some of the alloying elements separate

from the general mass of material.

SINK – A negative surface imperfection that is smooth and shallow

caused by volumetric shrinkage of wax or hot isostatic pressing of
castings.

SUPERFICIAL IMPERFECTION – An imperfection which disrupts the surface

and appears smooth-edged but does not penetrate the specified surface
roughness. This condition is so slight, that there is no measurable
depth.

20
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

9.3 Abbreviations. Abbreviations and symbols are in accordance with

ASME Y14.38 with the following additions:

And & High Pressure Turbine HPT

Augmentor AGMT Integrated INTEG
Axial AX Low Pressure Turbine LPT
Cobalt CO Outlet Guide Vane OGV
Commercial COML Rear RE
First Made For FMF Variable Area
Bypass Injection VABI

21
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

SPECIFICATION APPROVAL SHEET

SPECIFICATION TITLE: INTERPRETATION OF DRAWING

22
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only

 P1TF108-S5

REVISION HISTORY

P1TF108-S1 Initial Issue 08-13-02

-S2 CID 079666, CID 079745 02-02-07
-S3 CID 558531 10-30-14
-S4 CID 558595 06-26-15
-S5 CID 558976 01-08-21

*DENOTES LATEST REVISION

23
GE PROPRIETARY INFORMATION
Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

GE Designated: CONFIDENTIAL – authorized distribution only