TOOLING U - BASICS OF TOLERANCE
121 CORRECT 100%
Abrasive - ANSWER A material or tool consisting of hard particles used to wear down,
rub away, or machine material. Abrasive materials are often used in finishing
operations.
Accuracy - ANSWER The difference between a measurement reading and the true
value of that measurement. The less error present in the measurement, the more
accurate the results.
Allowance - ANSWER The difference between the smallest permissible hole and the
largest permissible shaft. An allowance creates a certain kind of fit between mating
parts.
Bilateral Tolerances - ANSWER A tolerance method using an equal plus and minus
deviation from the specified dimension. Bilateral tolerances are preferred if deviation in
either direction risks exceeding the absolute limits and can be equal or unequal.
Blueprint - ANSWER A document that contains the instructions necessary to
manufacture and/or assemble a part. The designer includes the degree of tolerance
necessary for the part to function as intended in the blueprint.
Casting - ANSWER A manufacturing process that involves pouring a heated liquid
material into a hollow mold until the material cools into a solidified shape. Casting
creates a part surface with no clear lay.
Clearance - ANSWER A fit that allows intentional space to exist between a hole and the
shaft inserted into it. For a clearance fit, the shaft diameter is designed to be slightly
smaller than the hole.
Interference - ANSWER A tight fit designed where the smallest permissible shaft is
larger than the largest permissible hole. Force is required to assemble parts with an
interference fit.
Lapping - ANSWER An abrasive process that removes the last bit of unwanted material.
A lapping process sometimes uses an abrasive paste that is rubbed across the part to
gradually smooth it.
Lay - ANSWER The overall direction of the pattern created by the production process.
Lay cannot be measured because it indicates only a direction.
121 CORRECT 100%
Abrasive - ANSWER A material or tool consisting of hard particles used to wear down,
rub away, or machine material. Abrasive materials are often used in finishing
operations.
Accuracy - ANSWER The difference between a measurement reading and the true
value of that measurement. The less error present in the measurement, the more
accurate the results.
Allowance - ANSWER The difference between the smallest permissible hole and the
largest permissible shaft. An allowance creates a certain kind of fit between mating
parts.
Bilateral Tolerances - ANSWER A tolerance method using an equal plus and minus
deviation from the specified dimension. Bilateral tolerances are preferred if deviation in
either direction risks exceeding the absolute limits and can be equal or unequal.
Blueprint - ANSWER A document that contains the instructions necessary to
manufacture and/or assemble a part. The designer includes the degree of tolerance
necessary for the part to function as intended in the blueprint.
Casting - ANSWER A manufacturing process that involves pouring a heated liquid
material into a hollow mold until the material cools into a solidified shape. Casting
creates a part surface with no clear lay.
Clearance - ANSWER A fit that allows intentional space to exist between a hole and the
shaft inserted into it. For a clearance fit, the shaft diameter is designed to be slightly
smaller than the hole.
Interference - ANSWER A tight fit designed where the smallest permissible shaft is
larger than the largest permissible hole. Force is required to assemble parts with an
interference fit.
Lapping - ANSWER An abrasive process that removes the last bit of unwanted material.
A lapping process sometimes uses an abrasive paste that is rubbed across the part to
gradually smooth it.
Lay - ANSWER The overall direction of the pattern created by the production process.
Lay cannot be measured because it indicates only a direction.
