Bill of Materials - 9: Assembly Blueprints
|WARNING: Machine tools present a safety hazard. Improper operation can result in severe injury. These topics are for non-laboratory study only and are not to be used in conjunction with the operation of any tool or machine described herein. Never use a machine tool without the supervision of a qualified instructor.|
|There are two types of assembly blueprints commonly used in machine shops: General Assembly and Detail Assembly (next page).
The General Assembly blueprint is the most common, and shows the final assembly of the product, and identifies all the individual parts by arrows and numbered balloons.
The example General Assembly blueprint shown above contains the following:
- 2 machined parts (items 1 and 7)
Altogether, 10 different items are indicated in the B/M items column. By adding the numbers in the quantity column it can be seen that there are 16 individual pieces, plus an unspecified amount of adhesive, to build the assembly.
Detail blueprints of the machined and/or fabricated parts will be found on separate blueprint sheets with different blueprint numbers.
|The Detail Assembly drawing is different from the General Assembly drawing, and is used by some commercial shops and occasionally in the aerospace/defense industries for prototype work. The Detail Assembly drawing shows all the individual parts and also includes dimensions and fabrication instructions on the assembly drawing.
The animation shows an assembly drawing with two detailed parts on the assembly sheet.
Sometimes a bill of material is skipped entirely and the information for the detail is listed below the detail itself:
"Tube, (1) req, 1.0 Dia mild steel"
label: BOM. bill of material, item numbers, key numbers, material specifications, assembly blueprint, subassembly, dash numbers and vehicles