The main goal of a fastener print is to provide the manufacturer the information needed for accurate fabrication.
In most cases, fastener prints have dimensions, materials, mechanical properties, and plating requirements specified on them. However, if the information is over specified, the cost of the fastener may increase when compared to the cost of an industry standard fastener with similar specifications.
Are you over specifying material for the application? Can you use 18-8 stainless steel instead of 304 stainless steel? Is the raw material specified as 4037 with Grade 8 mechanical properties? Grade 8 mechanical properties can be met with many different raw material grades and specifying a specific raw material limits the availability of standard parts.
If your print cites a specific material that the manufacturer typically doesn’t use for that grade, the manufacturer will have to process a separate order for your fastener, which will increase costs.
Reviewing/Understanding Finish Requirements
There are several variations of corrosion protection for your fastener and that protection will be dependent upon application of the product. There is no correct or perfect finish for every application. With the move towards environmentally safer finishes, old requirements many need to be reviewed and/or updated. Color of modern trivalent finishes is accomplished with dyes and no longer has an effect on the performance of the finish itself.
The environment where the end product will be used and the expected service life of the product are the two most important factors to consider when selecting your finish.
Fastener Application: Strength vs. Industry Standard
Your print specifies a Grade 8 bolt, the washer and nut are non-hardened, and you’re bolting two pieces of aluminum together. In this scenario you may not need the Grade 8 bolt, in other cases you can have identical fasteners with different strengths that can be combined to reduce inventory, eliminate SKU’s, and improve lead time.
Are you specifying fastener grades that are not available in the market, and is your volume too low for special manufacturing production?
Special Fastener Dimensions
The overall length of your hex head cap screw is 2-1/2” the tolerances on your print are ±0.030, making it a special fastener. Tolerances for standard hex cap screws are +0.000 and -0.000 depending on diameter and length.
Providing as much information as possible is typically the best option, but sometimes this information can affect the cost of the fastener. Sometimes, specifying the thread size, length, and grade may give you the lowest cost fastener.
Torx, Taptite, Fastite, Plastite, KEPS, SEMS, Crimptite, TEKS, among others, are all trademarked names. Did you know by listing a trademarked name on your print you are actually increasing your cost? These items are no longer under US Patent and have commercially available alternatives that have similar dimensions and performance characteristics.
If your print lists these trademarked features you should be receiving these fasteners manufactured by licensed manufactures. If you’re not concerned with the name brand and are looking for the performance of the licensed feature, an alternative can be supplied without paying the royalties.
One of the many benefits of working with Field is having access to our engineering experts. They will take the time to review your prints and come to you with proactive cost savings initiatives that will likely save your organization time and money upon implementation.