Question
A circular shaft having diameter 
mm is manufactured by turning process.
A 50 μm thick coating of TiN is deposited on the shaft. Allowed variation in TiN film
thickness is ±5 μm. The minimum hole diameter (in mm) to just provide clearance fit is
Options :
65.01
65.12
64.95
65.10
Answer :
65.12
Solution :
Shaft mm
Coating thickness 50 + 5um
Clearance fit
This is a question if clearance fit, for just clearance fit min. C will be zero. Therefore UL of shaft = LL of hole.
After coating largest shaft will be product if we start with largest shaft and add maximum coating.
tmax = 55 µm = 0.055 mm
Largest shaft after plating = 0.055 + 65.01 + 0.055 mm = 65.12 mm
Copyright © 2025 Test Academy All Rights Reserved