Workshop Viva Quick Reference Guide (Kant)

PAPERCODE: ES-164
PAPER: WORKSHOP TECHNOLOGY
UNIT I: SAFETY, PRECAUTIONS AND MAINTENANCE
Workshop Safety Fundamentals
Category Key Points
Personal • Always wear appropriate PPE (safety glasses, gloves, footwear, aprons)•
Safety Remove jewelry, loose clothing, and tie back long hair• Never work when tired or
under influence of medication/alcohol• Know emergency exit routes and assembly
points
Machine • Never operate without proper training• Use machine guards at all times•
Safety Maintain proper distance from moving parts• Never leave running machines
unattended• Use proper work-holding devices (not hands)
Electrical • Inspect cords/plugs before use• Never operate with wet hands or in wet areas•
Safety Use GFCI protection for portable tools• Know location of main power disconnect•
Only qualified personnel should repair electrical equipment
Fire Safety • Know location of fire extinguishers and their classes (A,B,C,D)• Keep
flammable materials away from heat sources• Store combustibles properly•
Maintain clear access to fire exits and equipment• Know evacuation procedures

Safety Devices
Device Purpose
Machine Guards Physical barriers preventing contact with moving parts
Emergency Stops Red mushroom buttons for immediate machine shutdown
Two-Hand Controls Require both hands to start machine, keeping hands away
from danger zones
Light Curtains Photo-electric beams that stop machine if interrupted
Interlocks Prevent machine operation when guards are open
Ground Fault Circuit Prevent electrical shock by detecting imbalance in current
Interrupters (GFCI)
Thermal Overload Protectors Prevent motor damage from excessive current
Safety with Moving Machine Parts
Part Type Hazards Precautions
Rotating Parts Entanglement, • Ensure guards are in place• No loose
drawing in, crushing clothing/jewelry• Maintain safe distance• Use proper
tools for adjustments (not hands)
Reciprocating Crushing, shearing, • Never reach into motion path• Use guards/barriers•
Parts impact injuries Lockout during maintenance
Cutting Tools Lacerations, • Keep sharp and properly maintained• Use
punctures, appropriate feeds and speeds• Use proper holding
amputations devices• Never clear chips by hand

Drive Systems Safety

Drive
Type Hazards Precautions
Chain Entanglement, • Use enclosed guards• Check tension regularly• Lubricate
Drives crushing, severing properly• Inspect for damaged links
Belt Entanglement, friction • Always guard pulley and belt• Check alignment and
Drives burns, impact tension• Replace worn/damaged belts• Never adjust while
running
Rope Entanglement, friction • Ensure proper tensioning• Use guards/enclosures• Check
Drives burns, whipping for fraying/wear• Keep lubricated if applicable

Electrical Safety
Aspect Key Points
Common • Electric shock/electrocution• Electrical burns• Fires from overheated wiring•
Accidents Arc flash injuries• Falls after shock
Prevention • Use properly grounded equipment• Inspect insulation before use• Use correct
fuses/breakers• Keep electrical panels accessible• Use lockout/tagout
procedures during maintenance
Emergency • Cut power before helping shock victims• Know CPR procedures• Report all
Response electrical incidents• Never use water on electrical fires

Maintenance Types
Type Features Benefits
Predictive • Based on condition monitoring• Uses • Minimizes downtime• Optimizes
Maintenance sensors, vibration analysis, component life• Reduces
thermography• Predicts failures before unexpected failures• Most cost-
they occur effective long-term
Preventive • Scheduled based on time/usage• • Reduces unplanned downtime•
Maintenance Regular inspections and service• Extends equipment life• Creates
Replacement of parts before failure• predictable maintenance schedule•
Type Features Benefits
Follows manufacturer recommendations Better than reactive maintenance
Scheduled • Fixed time intervals regardless of • Simple to implement• Ensures
Maintenance condition• Routine tasks performed on regular attention• Helps catch
schedule• Documentation of all activities problems early• Creates
maintenance discipline

Maintenance Standard Guidelines

Guideline Description
Documentation Maintain logs of all maintenance activities, inspections, and repairs
Manufacturer Specs Follow OEM recommendations for maintenance intervals and
procedures
Trained Personnel Only qualified technicians should perform maintenance tasks
Lockout/Tagout Always isolate energy sources before maintenance work
Proper Tools Use correct tools and calibrated measuring equipment
Cleanliness Keep equipment clean and work area organized
Lubrication Follow proper lubrication schedules and use correct lubricants
Spare Parts Maintain inventory of critical spare parts
Testing Verify proper operation after maintenance before returning to
service
Continuous Review maintenance practices regularly for optimization
Improvement

UNIT II: MACHINE SHOP

Lathe Machine
Aspect Details
Basic Machine that rotates workpiece about an axis for cutting operations
Description
Main Parts • Bed• Headstock• Tailstock• Carriage• Lead screw• Feed rod• Chuck/centers
Operations • Turning• Facing• Boring• Threading• Knurling• Taper turning•
Parting/cutting off• Drilling
Sample Job Step turning: Creating multiple diameter sections on a single workpiece
Safety Points • Never leave chuck key in chuck• Remove chips with brush, not hands•
Secure workpiece properly• Keep hands away from rotating parts

Milling Machine
Aspect Details
Basic Machine using rotating cutter to remove material from stationary workpiece
Description
Aspect Details
Main Parts • Base• Column• Knee• Saddle• Table• Spindle head• Arbor
Types • Horizontal milling• Vertical milling• Universal milling
Operations • Plain milling• Face milling• Side milling• Slot milling• Angular milling•
Form milling• Gear cutting
Sample Job Rectangular block with dado cuts and slots
Safety Points • Secure workpiece in vise• Use proper cutting speeds/feeds• Never adjust
workpiece while cutter is moving• Clear chips with brush

Shaper Machine
Aspect Details
Basic Machine using single-point cutting tool with reciprocating motion
Description
Main Parts • Base• Column• Cross rail• Ram• Tool head• Table• Clapper box
Operations • Horizontal surfaces• Vertical surfaces• Angular surfaces• Keyways•
Grooves• Dovetails
Sample Job V-block with flat and angular surfaces
Safety Points • Ensure work is securely clamped• Stand clear of ram movement• Never
measure while machine is running• Be aware of pinch points

Planer Machine
Aspect Details
Basic Similar to shaper but workpiece moves reciprocally under stationary tool
Description
Main Parts • Bed• Table• Columns• Cross rail• Tool heads• Driving mechanism
Operations • Large flat surfaces• Parallel surfaces• Angular surfaces• Grooves and slots•
Large workpieces
Sample Job Large machine base with parallel surfaces
Safety Points • Ensure table travel path is clear• Secure workpiece firmly• Use proper
cutting speeds• Be aware of table movement area

Grinding Machine
Aspect Details
Basic Machine using abrasive wheel for precision material removal
Description
Types • Surface grinder• Cylindrical grinder• Tool and cutter grinder• Centerless
grinder
Operations • Flat surface grinding• Cylindrical grinding• Internal grinding• Tool
sharpening• Form grinding
Aspect Details
Sample Job Precision flat plate or gauge block
Safety Points • Inspect wheel before use• Use eye protection and dust collection• Dress
wheel regularly• Never stand in line with rotating wheel

Drilling Machine
Aspect Details
Basic Machine using rotating drill bit to create holes
Description
Types • Bench drill• Pillar drill• Radial drill• Gang drill
Operations • Drilling• Reaming• Boring• Counterboring• Countersinking• Tapping
Sample Job Flange with multiple holes and countersinks
Safety Points • Clamp work securely• Remove chips with brush• Use recommended speeds
for material• Remove chuck key before starting

UNIT III: WELDING SHOP

Welding Fundamentals
Aspect Details
Definition Process of joining metals by heating to fusion temperature with or without
pressure and filler material
Classification • Fusion welding (melting base metals)• Pressure welding (application of
pressure)• Brazing (using filler with melting point below base metal)• Soldering
(using low melting point filler)
Common • Welding machine• Electrodes/filler rods• Welding helmet/goggles• Chipping
Tools hammer• Wire brush• Tongs• Protective clothing

Gas Welding (Oxy-Acetylene)

Aspect Details
Equipment • Oxygen cylinder (blue)• Acetylene cylinder (maroon)• Pressure regulators•
Hoses (green/red)• Torch and tips• Spark lighter• Safety valves
Process • Mixing oxygen and acetylene to produce flame (3200°C)• Melting base metal
and filler rod• Creating fusion joint upon cooling
Flame • Neutral flame (balanced O₂/C₂H₂)• Carburizing flame (excess acetylene)•
Types Oxidizing flame (excess oxygen)
Applications • Sheet metal work• Pipe joining• Repair work• Brazing• Cutting with attachment
Safety • Check for leaks with soap solution• Keep cylinders upright and secured• Never
use oil near oxygen• Store cylinders separately
Arc Welding
Aspect Details
Equipment • Power source (AC or DC)• Electrode holder• Ground clamp• Electrodes•
Welding helmet• Protective clothing
Process • Electric arc between electrode and workpiece (5000°C)• Melting base metal
and electrode coating• Slag formation protects weld pool
Types • Shielded Metal Arc Welding (SMAW/stick)• Metal Inert Gas (MIG/GMAW)•
Tungsten Inert Gas (TIG/GTAW)• Submerged Arc Welding (SAW)
Applications • Structural steel• Pipelines• Pressure vessels• General fabrication• Heavy
equipment
Safety • Use proper eye protection (shade #10-13)• Protect from UV radiation• Ensure
proper ventilation• Avoid electric shock (dry gloves/insulation)

Edge Preparation for Welding

Joint Type Edge Preparation Application
Butt • Square edges (up to 5mm)• Single V (5-12mm)• Pressure vessels, pipes,
Joint Double V (>12mm)• U-groove for thick sections structural members
Lap Joint • Clean surfaces• Overlap 3-5 times material thickness Sheet metal, automotive
panels
T-Joint • Square edges• Single bevel for full penetration• Structural frameworks,
Double bevel for thick sections brackets
Corner • Square edges• Single bevel for strength Boxes, frames, enclosures
Joint
Edge • Clean square edges• Slight gap for penetration Sheet metal edges, thin
Joint plates

Welding Joints Formation

Joint
Type Gas Welding Technique Arc Welding Technique
Butt • Forehand technique• 60-70° torch • 70-80° electrode angle• Slight weaving
Joint angle• Weave motion for wider bead motion• Multiple passes for thick
material
Lap • Forehand technique• Heat both pieces • Work at 45° angle• Ensure fusion into
Joint equally• Filler rod at leading edge of pool both pieces• Control penetration
carefully
T-Joint • Heat vertical piece more• Circular • 45° electrode angle• Slight pause at
motion with torch• Add filler to create edges• Balance heat between pieces
triangle fillet
Corner • Equal heat to both edges• Maintain • Electrode at 45° to both faces• Ensure
Joint consistent torch angle corner penetration• Watch for burn-
through
Joint
Type Gas Welding Technique Arc Welding Technique
Edge • Fast travel speed• Minimal filler • Use lower current• Fast travel speed•
Joint material• Control heat to prevent Tack weld before full weld
distortion

UNIT IV: SHEET METAL & FITTING SHOP

Sheet Metal Shop
Aspect Details
Common • Snips (straight/curved/aviation)• Measuring tools• Scribers and punches•
Tools Hammers (ball peen/mallets)• Stakes and mandrels• Folding bars• Shears and
brakes
Operations • Marking and measuring• Cutting and shearing• Bending and folding• Seaming
and hemming• Riveting• Soldering

Sheet Metal Operations

Operation Description Application
Shearing Cutting sheet metal along straight line Creating blanks, trimming
Bending Forming angular shapes by folding Creating corners, edges
Drawing Forming sheet into hollow shapes Creating containers, cups
Stretching Expanding metal over form Creating curved surfaces
Shrinking Compressing metal to create curves Creating concave forms
Hemming Folding edge over for strength/safety Reinforcing edges
Seaming Joining sheets by folding edges together Connecting separate pieces

Box Formation using Sheet Metal

Step Process
1. Pattern • Calculate dimensions including allowances for joints• Mark out pattern
Development with height, width, length, and tabs
2. Cutting • Cut external outline with snips or shears• Cut notches at corners
3. Bending • Bend along fold lines using brake or folding bars• Create 90° bends for
sides
4. Corner • Form corners using appropriate joint (lap, hemmed, etc.)• Secure with
Formation solder, rivets, or lock seams
5. Finishing • Remove sharp edges• Apply surface treatment if needed• Inspect for
quality
Fitting Shop
Aspect Details
Definition Workshop for assembly of parts through non-permanent joining methods
Common • Files (flat, round, half-round, etc.)• Hacksaws• Chisels and punches• Hammers•
Tools Measuring tools (steel rule, vernier caliper, etc.)• Drill and tap sets• Bench vises•
Scrapers

Fitting Tools and Applications

Tool Types Applications
Files • Rough/second cut/smooth• Flat/round/half- • Removing material• Finishing
round/square/triangular surfaces• Deburring edges
Hacksaw • Fixed frame• Adjustable frame• Blades • Cutting metal stock• Creating slots•
(14-32 TPI) Cutting profiles
Chisels • Flat• Cross-cut• Diamond point• Round • Cutting grooves• Removing excess
nose material• Breaking castings
Hammers • Ball peen• Cross peen• Straight peen• Soft- • Striking chisels• Riveting•
faced Bending• Assembly
Scrapers • Flat• Three-square• Half-round • Creating high-precision flat
surfaces• Removing high spots

Common Fitting Shop Jobs

Job Description Skills Practiced
V-Block Metal block with V-groove for holding Filing, marking, measuring,
round stock squaring
Male-Female Interlocking parts with precise fit Precise filing, measurement,
Joint finishing
Square Fitting Creating perfect square from round Filing, checking squareness,
stock precision work
Dovetail Fitting Creating sliding dovetail joint Layout, filing, precision fitting
Step Fitting Creating steps of specific dimensions Accurate measurement, filing to
line
Drill Gauge Plate with various sized holes Layout, drilling, reaming, finishing

IMPORTANT VIVA QUESTIONS

Safety and Maintenance
1. Q: What is lockout/tagout procedure? A: Procedure to disable machinery
during maintenance by isolating energy sources, locking the disconnect, and
tagging it to prevent accidental startup.
 2. Q: Name three types of fire extinguishers and their applications. A: Type A
(water) for ordinary combustibles, Type B (CO₂ /foam) for flammable liquids,
Type C (dry chemical) for electrical fires.
3. Q: What is the difference between preventive and predictive maintenance?
A: Preventive is time-based regardless of condition; predictive is condition-based
using monitoring to predict failures before they occur.

Machine Shop
1. Q: What is the purpose of back gear in a lathe? A: To reduce spindle speed
while increasing torque for heavy cutting operations.
2. Q: Differentiate between up milling and down milling. A: In up milling, cutter
rotates against feed direction (conventional); in down milling, cutter rotates with
feed direction (climb milling).
3. Q: Why is cutting fluid used in machining? A: For cooling, lubrication, chip
removal, and extending tool life.

Welding Shop
1. Q: What causes porosity in welds? A: Gas entrapment due to moisture,
contaminants, improper gas coverage, or incorrect electrode handling.
2. Q: Differentiate between forehand and backhand welding techniques. A: In
forehand, torch points in direction of welding; in backhand, torch points opposite
to welding direction.
3. Q: Why must acetylene pressure not exceed 15 psi? A: Acetylene becomes
unstable and may spontaneously decompose/explode above this pressure.

Sheet Metal and Fitting

1. Q: Why is allowance given for sheet metal bends? A: To compensate for
material stretching/compression during bending to achieve accurate final
dimensions.
2. Q: What is the difference between a seam and a hem? A: A seam joins two
separate pieces; a hem is folding the edge of a single sheet back on itself.
3. Q: What is the purpose of draw filing? A: To produce smoother finish by
holding file sideways and pushing/pulling lengthwise along the workpiece.