Cover Image
close this bookFundamentals of Fitting - Course: Techniques of Fitting and Assembling Component Parts to Produce Simple Units. Instruction Examples for Practical Vocational Training
View the document(introduction...)
View the documentPreliminary Remarks
View the documentInstruction Example 31.1. Mitre Angle Gauge
View the documentInstruction Example 31.2. Square Bolt for Three-jaw Chuck Wrench
View the documentInstruction Example 31.3. Locking handle for Three-jaw Chuck Wrench
View the documentInstruction Example 31.4. Keyed Joint of Pulley and Shaft

Instruction Example 31.3. Locking handle for Three-jaw Chuck Wrench

Practising of the fitting of bores in preparing pinned joints by manual reaming.

Material


Figure

- square bolt from the 2. instruction example
- round stock made of steel (380 MPa)

diameter: 32 mm
length: 36 mm

- cylindrical pin

Æ 10 m 6
length: 80 mm

- cylindrical pin

Æ 6 m 6
length: 36 mm

Tools

Marking-out tool, centre punch, hammer, aluminium hammer, drills Æ 15.8 mm, Æ 9.8 mm, Æ 5.8 mm, countersink of 90°, cylindrical hand reamers Æ 16 E 8, Æ 10 H 8, Æ 6 H 8

Measuring and testing means

Steel rule, vernier caliper, centre square

Auxiliary accessories

Vice, machine vice with Vee-jaws, boring emulsion, cutting oil, tap wrench, machine grease

Necessary previous knowledge

Manual working of materials - measuring, testing, marking, boring, countersinking, reaming

Sequence of operations

Comments



1. Prepare the workplace, make the working material available




2. Drill the central bore hole for the insertion of the square bolt into the head by drilling up to Æ 15.8 mm and spot-facing on both sides to 16.2 mm

- Clamp the workpiece so that it cannot twist



3. Ream the bore with the hand reamer to Æ 16 E 8

- Stage (1)



4. Insert the square bolt by hand

- Clearance fit; mating parts move easily into each other



5. Make the precision bore for the lock Æ 10 m 6 with the hand reamer Æ 10 H 8

- Stage (2) boring, countersinking, reaming



6. Insert the slightly greased lock with the aluminium hammer

- Interference fit; fitting together takes greater efforts



7. Finish the precision bore for the fitting pin Æ 6 m 6 with the hand reamer Æ 6 H 8

- Stage (3) bore a hole which is stepped to the lock by 90°



8. Drive in the slightly greased fitting pin with the aluminium hammer

- Interference fit



9. Check the interference fits for tightness (mating parts must be snugly fitting)



Figure