Instruction example 1.3.: Tap wrench

To practise length measurements of higher level of difficulties with exact finding of measuring points, exact reading of measured values for fine measurements, measuring of an angle.

Material

Common tap wrench of small or medium size.

Figure

Measuring and testing tools

Steel measuring tool, vernier caliper. protractor.

Accessories

Working place with a seat, soft support for measuring and testing tools (rag), well-lighted working area, pencil for entries in the table of values.

Required previous knowledge

Reading of drawings, knowledge of decimal numbers and length units, construction and reading of verniers of vernier calipers and of scales of protractors.

Sequence of operations	Comments
1. Arrange the working place, prepare the working materials.	- Put measuring and testing tools on soft rag. Lay out pencil and drawing with table in easy reach.
2. Measure sizes no. (1) to (3) and (5) to (8) with steel measuring tool and enter values in table of values.	- Entry in column "coarse" in 1 mm measuring accuracy.
3. Measure sizes no. (1) to (9) with vernier caliper and enter values in table of values,	- Entry in column "fine" in 0,1 mm measuring accuracy.
4. Measure size no. (10) with protractor and enter value in table of values.

To continue practising, if necessary:

Further sizes to be specified by the instructor and to be measured.

Tap Wrench