Engineering Drawings&

Measurements

Information on a Drawing

• Materials• Surface Finish• Dimensions• Tolerances• Drawing Scale• Assembly/Subassembly• Finish• Revision• Special Notes•Part Name

Suface Finish

Measured in microinches.Microinch = one millionth of an inch..000001”The larger the number, the rougher the finish.

Dimensions

Fractional

Decimal

Tolerances

Limits: Indicate the upper and lower limit of the tolerance.

Unilateral: Tolerance extends in only one direction.

Bilateral: Tolerance extends in both directions.

TolerancesCheck the titleblock for general tolerances not specified on the drawing.

Unless otherwise specified fractional tolerance +/- 1/64”.

Parts List

Identify all of the components necessary in order to assemble the product.

Measurements

Steel Rule

• Used to measure with only.• Keep clear of moving machinery.• Avoid laying other tools on the rule.• Wipe with an oily cloth before storing.• Clean with steel wool.• Make measurements from 1” line.• Store rules separately.

Micrometer

• Place micrometer on work carefully so anvil face and spindle will not be damaged.• Keep clean. Wipe with oily cloth.• Avoid springing a micrometer.• Clean anvil and spindle before use.

Micrometer

•Avoid placing where it may fall or have other tools on top of it.• Roll the thimble not the frame.• Never make a micrometer reading until a machine has come to a complete stop.

Vernier Caliper / Digital Caliper

• Outside diameter.• Inside diameter.• Hole depth.• Back of caliper for height or length.

Vernier Caliper / Digital Caliper

• Never force the tool when making measurements.• Handle as little as possible.• Check for accuracy.• Lay height gages on their side.

Gages• Plug gage• Ring gage• Thread gage• Gage blocks• Screw Pitch• Radius