SECTION 1.5
Tool Drawings

A broach tool designer must have a strong background in drafting and mechanical drawing to properly present design concepts to the people who will be making the proposed tool. For the most part, broach makers do not require the same type of drawings as do the less experienced machine operators in a production environment. For this reason, tool drawings can be drawn much simpler and quicker to keep the design cost to a minimum. The following are a few basic points to remember when creating or reviewing tool drawings.

1. Draw and dimension with due consideration for someone using the drawing to manufacture a tool.
   1. Do not crowd views or dimensions.
   2. Analyze each operation to be sure it can be done with available (or easily obtainable) equipment.
   3. Do not put process information on the drawing. If a specific operation is required, create a process sheet to accompany the design print.
      
2. Use only as many views as necessary to show all required detail. Excess section views complicate a drawing.
3. Tolerances and fits peculiar to broach cutting tools require extra thought. It is not economical to "over-tolerance" a feature that does not require it.
4. The broach tool drawing must indicate all sizes required to obtain stock for the tool. It is necessary to allow material for finishing in almost all cases. As far as possible, stock sizes known to be on hand should be used.
5. Use notes only to convey ideas that cannot be communicated by geometric dimensioning and tolerancing (ANSI Y14.5M-1982) and ordinary drawing.
6. Secondary operations, such as machining of edges, polishing, or similar specifications should be kept to a minimum. Only employ these operations when they are important to the overall fit or function of the tool; otherwise these operations will only add cost, not quality to the tool.
7. Apply tolerances realistically (see Section 1.6). Overly tight tolerances can add a great deal of additional cost with little or no added value to the tool. The fit or function of the tool feature should determine the specific tolerance, not a standard title block tolerance value.
8. If tooling is to be duplicated in whole or part or if multiple tools are required, drawings should be well detailed.

SECTION 1.5.1
Engineering drawing review

Engineering drawings which are supplied by the customer will include significant characteristics shown on the control plan. However, when no customer engineering drawing exists, as in the case of proprietary designs, the controlling drawings must have written approval by the customer in order to verify which dimensions affect fit, function, and durability, as well as governmental regulatory or safety requirements. These features can usually be found in a customer engineering specification, through previous service or warranty experience, or on assembly drawings.

In any case, all drawings should be submitted to the design review process to determine if there are sufficient dimensions to manufacture the tools without the operator having to calculate any dimensions. (This will greatly facilitate set-up, reduce operator error, and minimize inspection error.) All dimension, control, and datum lines should be clearly identified so that the appropriate functional micrometers, gages, and blocks can be made available for ongoing controls. All dimensions should be evaluated to determine if they are containable and compatible with available manufacturing capabilities.

SECTION 1.5.2
Drawing and change control

The broach tool design engineering department is responsible for providing the customer with current engineering drawings and specifications as outlined in the purchase order. The designer is responsible for understanding the customers' part requirements. Joint planning involving the designer, sales representative, and the customer may be required in order to establish a clear comprehension and interpretation of blueprints, part prints, specifications, materials, manufacturing methods, checking methods, and significant characteristics. If any questionable areas exist, the designer must contact the customer immediately for clarification. Written approvals of a new design (especially approval of the characteristics which are significant to the customer) are to be received from the customer before the design can be released for manufacturing.

The broach tool design engineering department must maintain the latest engineering drawings and specifications and insure that all of the necessary engineering documents are available in the event of customer inquiry, customer changes/revisions, or design obsolescence. Please note the following:

• Manufacturing notes added to blueprints or process sheets during the manufacturing process must be initialized by the operator making the addition. All manufacturing notes added must be made permanently on the manufacturing process sheets during the print review stage of a reorder.

• Process or drawing changes/revisions made during the manufacturing process must be initialized by a design engineer. All additions and changes must be made permanent on the engineering drawing or process sheet during the print review stage of a re-order.

• Any obsolete information must be removed from all points of use and either destroyed or identified to prevent misuse of obsolete information. All design changes affecting customer part dimensions or set-up must have written customer approval prior to being incorporated into manufacturing.