Allowances and Tolerances in Mechanical Engineering

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What is the difference between the nominal dimension and the upper and lower limit of size?

Fit
Tolerance (correct)
Allowance
Precision

What is the acceptable range for a precision cylindrical part?

The range is usually much smaller for mating cylindrical parts (correct)
The range is not specified for precision cylindrical parts
The range is usually much larger for mating cylindrical parts
The range is the same for mating cylindrical parts and sheet metal repairs

What is the purpose of an allowance in sheet metal work?

To specify the difference between the nominal dimension of a part and its upper or lower limit (correct)
To provide a range of acceptable sizes for a part
To specify the nominal dimension of a part
To specify the tolerance of a part

What is the upper limit of size minus the lower limit of size in a dimension with a tolerance of ±0.020 in?

0.020 in. (B) Signup and view all the answers

In aircraft drawings, what is the dimension tolerance assumed for a dimension given as a common fraction?

±1/64 in. (C) Signup and view all the answers

What is the difference between the upper and lower limit of size in a dimension with a tolerance of ±0.0005 in?

0.0010 in. (C) Signup and view all the answers

What is the purpose of an allowance in mating cylindrical parts?

To provide a difference between the maximum material limits of mating parts (A) Signup and view all the answers

What is the maximum material limit of a bolt?

The maximum diameter of the bolt (D) Signup and view all the answers

What is the result of a maximum diameter of a bolt being 0.001 in. less than the minimum diameter of the hole?

Positive allowance (A) Signup and view all the answers

What is the purpose of a clear system of labelling in precision tooling and equipment?

To indicate the inspection or calibration period (A) Signup and view all the answers

What information should a label on precision tooling and equipment show?

The date last tested, the next inspection or calibration date, and the authorised person's signature or stamp (C) Signup and view all the answers

What is the result of a maximum diameter of a bolt being 0.001 in. greater than the minimum diameter of the hole?

Negative allowance (C) Signup and view all the answers

What is the purpose of a nominal dimension in an aircraft drawing?

To state the size of a part as specified on the drawing (C) Signup and view all the answers

What is the difference between the nominal dimension and the upper and lower limits of size?

Tolerance (C) Signup and view all the answers

What is the purpose of upper and lower limits of size in precision cylindrical parts?

To ensure proper fit and function of a part (D) Signup and view all the answers

What is the symbol used to represent inches in drawings and dimensional specifications?

″ (double prime symbol) (A) Signup and view all the answers

What is the range of sizes within which a part is considered acceptable?

Upper and lower limits of size (D) Signup and view all the answers

Why is it important to consider tolerance when manufacturing precision cylindrical parts?

To ensure proper fit and function of a part (A) Signup and view all the answers