*Originally published September 28, 2001 by
Rick Ferenchick, VP Sales and Marketing
Sixteen “common sense” rules for achieving high quality and reducing in-house fastener costs.
- Determine if a standard design fastener will meet the design application objective.If a standard screw design already exists that will meet a design application objective, it is best to use it. Why? More readily available, faster delivery and in general, will cost less!
- Limit selection of standard types and sizesIt is good management to stock a larger inventory of fewer parts, thereby avoiding the higher costs of small quantity reordering. You will additionally save on the reduced variety of tooling required, i.e. punching, drilling etc.
- Use multi- function fastenersFasteners such as sems assemblies, thread forming, thread cutting, self sealers, etc., do more than just hold two parts together. They can be used to reduce the number of parts by having a single fastener perform the functions of two or more fasteners, thereby increasing production while at the same time cutting costs on assembly operations and minimizing rejections.
- Save by adding more commodity items to your company’s existing ship-to-stock “breadman” turnkey inventory control systemLeverage your existing cost savings even further by adding other commodity items, e.g. caplugs, electrical items, stampings, rubber parts, springs etc. The mechanics of the system are already in place, why not review an illustrated parts breakdown with the objective of targeting specific new items to add to the “breadman program”. To service these new items would be a relatively easy task for Arnold’s inside customer sales representative.
- Class 2a and 2b thread tolerance is best throughout the entire productThe most commonly used thread tolerance is class 2a external to suit class 2b internal threads. This allows for sufficient clearance to minimize fastener driving difficulties. Allow for commercial plating build-ups during design specification.
- Best to specify low carbon steelAlso, consider the cost savings on the least expensive non-ferrous materials, where these materials are adequate for the job.
- Adhere to the Industrial Fastener Institute standards “the industry bible” Fastener Standards Sixth EditionDesign engineers will reap dividends by keeping their design requirements as uncomplicated as possible, obviously, where possible.
- Communicate the fastener application in the early design stagesArnold sales staff may be able to suggest a more current design, a more efficient or less expensive fastener design. There is no cost associated with this “encyclopedia” of fastener application knowledge.
- Specify cold-headed partsCold-heading eliminates waste, increases shear strength, and offers a variety of head designs not possible with screw machine operations, all at substantial cost savings.
- Use recommended materials on adjacent partsAvoid galvanic action between non-compatible metals and finishes.
- Save by using plated fasteners where the application warrantsPlated screws will usually forestall surface reactions and corrosion. This is typically at a lower cost than screws made from solid materials. Food industry and salt water environment are notable exceptions.
- Custom designed fastenersBe money ahead by using cold-headed special designs wherever possible in place of screw machine parts. Cost savings are very significant.
- Avoid sharp cornersIt’s best to allow for a radius of .005 to .010 as since more critical tolerance will add to the cost.
- Provide most recent drawings and specificationsA sample part, if readily available, should accompany the drawing , etc.
- Specify IFI industry tolerances for additional cost savings– Diameters
These tolerances are adequate in most industries. However, closer tolerances required for special applications can be supplied by Arnold Industries.
- Your company & an Arnold Industries partnership– ISO 9002 certified
– Pioneer in turnkey in fastener inventory control systems
– Depth of engineering and customer service experience
– Significant cost savings for manufacturing
– Excellent inventory database