7.6 Flashcards
What size is biggest and smallest drill diameter?
Z biggest
A smallest
What are the 3 types of fit?
Clearance
Interference
Transition
How many classifications do ISO provide?
28
What are the 2 grades of bilateral holes?
A and B
What is the difference to class A and B?
Class A is more Accurate than class B
What are the 2 grades of press fit?
F and D
What’s the class of transition fit?
P
What are the 3 class of clearance fit?
Z, Y and X
What is the remark for interference (F) fittings?
Mechanical pressure
What is a remark for Driving (D) fittings?
Less tight than force fit one part can be driven into another
What is a remark for push (P) fittings?
Suitable for detachable parts but not moving
What is a remark for clearance/Running (X, Y Z) fittings?
What is special about Z
Suitable for moving Parts
Z is finest
What is deviation?
Difference between a size and corresponding size
What is FIt?
Mating shaft and hole
What is clearance?
And what does it allow
Shaft smaller than hole allows for movement
If a parts clearance becomes to large what are the 3 characteristics to look for to know its been worn?
Quality
Bow
Twist
How do they Heat/Shrink parts to fit in different assembly’s?
Heat with heating element
Shrink with dry ice or liquid nitrogen
What is a Press/Transition fitting?
Part is pressed into the assembly
What is a clearance fitting?
Parts are slid into the dedicated slot
When a shaft or tubes centre line is not straight what is it called?
And what can this cause when rotating at high speeds?
Bowing
Vibrations
For an example a shaft that rotates at 1500 Rpm what is the limit of Bow allowed?
0.25mm or 10’ thou
What is Wear?
Removal of material and deformation
What is Dimension New in relation to Wear?
Size of part when its new to relevant tolerances
What is Permissible Worn Dimension in relation to Wear?
Size which parts can wear before becoming unserviceable
