भारतीय मानक IS 18480 (Part 1) : 2023

ISO 7049 : 2011

Indian Standard

क्रॉस रिसेस्ड टै पपिंग पेंच

भाग 1 पैन हैड

Cross Recessed Tapping Screws

Part 1 Pan Head

ICS 21.060.20

 BIS 2023
 ISO 2011

भारतीय मानक ब्यरू ो

BUREAU OF INDIAN STANDARDS
मानक भवन, 9 बहादरु शाह ज़फर मार्ग, नई ददल्ली - 110002
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI - 110002
www.bis.gov.in www.standardsbis.in

November 2023 Price Group 5

General Engineering and Fasteners Sectional Committee, PGD 37

NATIONAL FOREWORD

This Indian Standard (Part 1) which is identical to ISO 7049 : 2011 ‘Cross-recessed pan head tapping
screws’ issued by the International Organization for Standardization was adopted by the Bureau of
Indian Standards on the recommendation of the General Engineering and Fasteners Standards
Sectional Committee and approval of the Production and General Engineering Division Council.

Cross recessed tapping screws are a type of fastener designed for efficiently joining two or more
materials together. These are externally threaded fasteners that ‘tap’ their own mating threads in
metallic and non-metallic (such as plastic) materials. Some screws require a hole, while others drill their
own hole (self-drilling). These screws feature a unique cross-shaped indentation on their head, which
corresponds to a specialized screwdriver or bit. This design allows for easy and secure driving of the
screw into the material.

Tapping screws are also sometimes called sheet metal screw. Cross recessed tapping screws can be
used for fastening objects to thin metal, wood or plastic. These screws are commonly used in a wide
range of industries, including woodworking, metalworking, electronics, automotive, and more.

This standard is published in 3 parts. Other parts in this series are:

Part 2 Countersunk (flat) head

Part 3 Raised countersunk (Oval) head

The text of ISO standard has been approved as suitable for publication as an Indian Standard without
deviations. Certain conventions are, however, not identical to those used in Indian Standards. Attention
is particularly drawn to the following:

a) Wherever the words ‘International Standard’ appear referring to this standard, they should be
read as ‘Indian Standard’; and
b) Comma (,) has been used as a decimal marker while in Indian Standards, the current practice is
to use a point (.) as the decimal marker.

In this adopted standard, reference appears to certain International Standards for which Indian
Standards also exist. The corresponding Indian Standards, which are to be substituted in their
respective places, are listed below along with their degree of equivalence for the editions indicated:

International Standard Corresponding Indian Standard Degree of

Equivalence
ISO 225 Fasteners — Bolts, IS 8536 : 2021/ISO 225 : 2010 Identical
screws, studs and nuts — Fasteners — Bolts, screws, studs and
Symbols and descriptions of nuts — Symbols and descriptions of
dimensions dimensions (second revision)
ISO 1478 Tapping screws IS 5957 : 2003/ISO 1478 : 1999 Screw Identical
thread threads for thread forming tapping
screws dimensions (second revision)
ISO 2702 Heat-treated steel IS 7178 : 2018/ISO 2702 : 2011 Heat- Identical
tapping screws — Mechanical treated steel tapping screws —
properties Mechanical properties (fourth revision)

(Continued on third cover)

 IS 18480 (Part 1) : 2023
ISO 7049 : 2011

Indian Standard
CROSS RECESSED TAPPING SCREWS
PART 1 PAN HEAD

1 Scope
This International Standard specifies the characteristics of cross-recessed pan head tapping screws with
thread sizes from ST 2,2 to ST 9,5 inclusive.

2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

ISO 225, Fasteners — Bolts, screws, studs and nuts — Symbols and descriptions of dimensions

ISO 1478, Tapping screws thread

ISO 2702, Heat-treated steel tapping screws — Mechanical properties

ISO 3269, Fasteners — Acceptance inspection

ISO 3506-4, Mechanical properties of corrosion-resistant stainless steel fasteners — Part 4: Tapping screws

ISO 4042, Fasteners — Electroplated coatings

ISO 4757, Cross recesses for screws

ISO 4759-1, Tolerances for fasteners — Part 1: Bolts, screws, studs and nuts — Product grades A, B and C

ISO 8992, Fasteners — General requirements for bolts, screws, studs and nuts

ISO 10683, Fasteners — Non-electrolytically applied zinc flake coatings

ISO 16048, Passivation of corrosion-resistant stainless-steel fasteners

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IS 18480 (Part 1) : 2023
ISO 7049 : 2011

3 Dimensions
See Figure 1 and Table 1.

Symbols and descriptions of dimensions are specified in ISO 225.

a) Type C

b) Type F

c) Type R

d) Type H — Cross recess e) Type Z — Cross recess

a Dimension a shall be measured at the core diameter of the first full thread.

Figure 1 — Cross-recessed pan head tapping screw

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 IS 18480 (Part 1) : 2023
ISO 7049 : 2011

Table 1 — Dimensions
Dimensions in millimetres
Thread size ST 2,2 ST 2,9 ST 3,5 ST 4,2 ST 4,8 ST 5,5 ST 6,3 ST 8 ST 9,5
Pa 0,8 1,1 1,3 1,4 1,6 1,8 1,8 2,1 2,1
a max. 0,8 1,1 1,3 1,4 1,6 1,8 1,8 2,1 2,1
da max. 2,8 3,5 4,1 4,9 5,6 6,3 7,3 9,2 10,7
max. 4,00 5,60 7,00 8,00 9,50 11,00 12,00 16,00 20,00
dk
min. 3,70 5,30 6,64 7,64 9,14 10,57 11,57 15,57 19,48
max. 1,60 2,40 2,60 3,10 3,70 4,00 4,60 6,00 7,50
k
min. 1,40 2,15 2,35 2,80 3,40 3,70 4,30 5,60 7,10
r min. 0,10 0,10 0,10 0,20 0,20 0,25 0,25 0,40 0,40
rf ≈ 3,2 5,0 6,0 6,5 8,0 9,0 10,0 13,0 16,0
Recess No 0 1 2 3 4
m ref. 1,9 3,0 3,9 4,4 4,9 6,4 6,9 9,0 10,1
Type H max. 1,20 1,80 1,90 2,40 2,90 3,10 3,60 4,70 5,80
Cross Penetration
min. 0,85 1,40 1,40 1,90 2,40 2,60 3,10 4,15 5,20
recess
m ref. 2,0 3,0 4,0 4,4 4,8 6,2 6,8 8,9 10,1
Type Z max. 1,20 1,75 1,90 2,35 2,75 3,00 3,50 4,50 5,70
Penetration
min. 0,95 1,45 1,50 1,95 2,30 2,55 3,05 4,05 5,25
Type C 2,0 2,6 3,2 3,7 4,3 5,0 6,0 7,5 8,0
y ref. Type F 1,6 2,1 2,5 2,8 3,2 3,6 3,6 4,2 4,2
Type R — — 2,7 3,2 3,6 4,3 5,0 6,3 —

lb
Type C Type F
and
Type R
nom. min. max. min. max.
4,5 3,7 5,3 3,7 4,5 — — — — — — — —
6,5 5,7 7,3 5,7 6,5 — — — — — — —
9,5 8,7 10,3 8,7 9,5 — — — —
13 12,2 13,8 12,2 13,0 Range — —
16 15,2 16,8 15,2 16,0 of
19 18,2 19,8 18,2 19,0 preferred
22 21,2 22,8 20,7 22,0 lengths
25 24,2 25,8 23,7 25,0
32 30,7 33,3 30,7 32,0
38 36,7 39,3 36,7 38,0
45 43,7 46,3 43,5 45,0
50 48,7 51,3 48,5 50,0
a P = pitch of the thread.
b Sizes with lengths marked with a dash (—) cannot be manufactured.

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IS 18480 (Part 1) : 2023
ISO 7049 : 2011

4 Specifications and reference International Standards

See Table 2.

Table 2 — Specifications and reference International Standards

Material Steel, in accordance with ISO 2702 Stainless steel

General requirements ISO 8992
Thread ISO 1478
Cross recess ISO 4757
Steel grade/ — A2-20H, A4-20H, A5-20H
Mechanical hardness class
property
International Standard ISO 2702 ISO 3506-4
Product grade A
Tolerances
International Standard ISO 4759-1
As processed
Requirements for electroplating are Requirements for passivation are
specified in ISO 4042. specified in ISO 16048.
Requirements for
non-electrolytically applied zinc
Finish — Coating flake coatings are specified in
ISO 10683.
Additional requirements or other
finishes or coatings shall be
agreed between the supplier and
the purchaser.
Acceptability Acceptance inspection is specified in ISO 3269.

5 Designation
EXAMPLE 1 A cross-recessed pan head tapping screw with thread size ST 3,5, nominal length l = 16 mm, made of
steel (St) in accordance with ISO 2702, rounded end (Type R) and cross recess Type Z is designated as follows:
Tapping screw ISO 7049 - ST 3,5 × 16 - St - R - Z

EXAMPLE 2 A cross-recessed pan head tapping screw with thread size ST 3,5, nominal length l = 16 mm, made of
stainless steel (A4-20H) in accordance with ISO 3506-4, rounded end (Type R) and cross recess Type H is designated as
follows:
Tapping screw ISO 7049 - ST 3,5 × 16 - A4-20H - R - H

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 IS 18480 (Part 1) : 2023
ISO 7049 : 2011

National Annex A
(National Foreword)

A-1 BIS CERTIFICATION MARKING

The product(s) confirming to the requirements of this standard may be certified as per the conformity
assessment schemes under the provisions of the Bureau of Indian Standards Act, 2016 and the Rules
and Regulations frames thereunder, and the product(s) may be marked with the Standard Mark.

5
 (Continued from second cover)

International Standard Corresponding Indian Standard Degree of

Equivalence

ISO 3269 Fasteners — IS 1367 (Part 17) : 2023/ISO 3269 : Identical

Acceptance inspection 2019 Technical supply conditions for
threaded steel fasteners: Part 17
Inspections, sampling and acceptance
procedure (fifth revision)
ISO 3506-4 Mechanical IS 1367 (Part 14/Sec 4) : 2023/ISO Identical
properties of corrosion- 3506-4 : 2009 Technical supply
resistance stainless steel conditions for threaded steel fasteners:
fasteners — Part 4: Tapping Part 14 Mechanical properties of
screws corrosion resistant stainless steel
fasteners, Section 4 Tapping screw
ISO 4042 Fasteners — IS 1367 (Part 11) : 2020/ISO 4042 : Identical
Electroplated coating systems 2018 Technical supply conditions for
threaded steel fasteners: Part 11
Electroplated coating systems (fourth
revision)
ISO 4757 Cross recesses for IS 7478 : 2011/ISO 4757 : 1983 Cross Identical
screws recesses for screws (second revision)

ISO 4759-1 Tolerances for IS 1367 (Part 2) : 2002/ISO 4759-1 : Identical

fasteners — Part 1: Bolts, 2000 Technical supply conditions for
screws, studs and nuts — threaded steel fasteners: Part 2
Product grades A, B and C Tolerances for fasteners — Bolts,
screws, studs and nuts — Product
grades A, B and C (third revision)
ISO 8992 Fasteners — General IS 1367 (Part 1) : 2014/ISO 8992 : 2005 Identical
requirements for bolts, screws, Technical supply conditions for
studs and nuts threaded steel fasteners: Part 1
General requirements for bolts, screws,
studs and nuts (fourth revision)
ISO 10683 Fasteners — Non- IS/ISO 10683 : 2018 Fasteners — Non- Identical
electrolytically applied zinc flake electrolytically applied zinc flake
coating systems coating systems

The Committee has reviewed the provisions of the following International Standard referred in this
adopted standard and has decided that it is acceptable for use in conjunction with this standard:

International Standard Title

ISO 16048 Passivation of corrosion-resistant stainless-steel fasteners

The standard also makes a reference to the BIS Certification Marking of the product, details of which
are given in National Annex A.

For the purpose of deciding whether a particular requirement of this standard is complied with, the final
value, observed or calculated expressing the result of a test or analysis, shall be rounded off in
accordance with IS 2 : 2022 'Rules for rounding off numerical values (second revision)'.The number of
significant places retained in the rounded off value should be the same as that of the specified value in
this standard.
Bureau of Indian Standards

BIS is a statutory institution established under the Bureau of Indian Standards Act, 2016 to promote harmonious
development of the activities of standardization, marking and quality certification of goods and attending to
connected matters in the country.

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Review of Indian Standards

Amendments are issued to standards as the need arises on the basis of comments. Standards are also reviewed
periodically; a standard along with amendments is reaffirmed when such review indicates that no changes are
needed; if the review indicates that changes are needed, it is taken up for revision. Users of Indian Standards
should ascertain that they are in possession of the latest amendments or edition by referring to the website-
www.bis.gov.in or www.standardsbis.in.
This Indian Standard has been developed from Doc No.: PGD 37 (23187).

Amendments Issued Since Publication

Amend No. Date of Issue Text Affected

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