Rapid Rivet has made some recent changes to our "Hold Ship Order" policy:
Rapid Rivet has a $25.00 minimum order requirement per purchase order for domestic (U.S.A.) shipments, and an $8.00 individual line minimum.
For international orders, a $50.00 USD minimum order requirement applies, and a $15.00 individual line minimum.
Although many aerospace suppliers are moving towards NADCAP certified special process, it is not considered standard per the scope of most aerospace / military specifications, and is still considered as a special request requirement. In most cases, Rapid Rivet is able to quote items with NADCAP special processes upon request. NADCAP special process would include plating and finishes, heat treating, annealing, passivation of stainless steel, and machining.
The "C" code is an obsolete designation that was used briefly in the 1989-1991 time period under MS20426 revision J, and MS20470 revision F. This code indicated chemical surface treatment per MIL-C-5541 Class 1A Gold/Yellow. Parts manufactured during the time period when these revisions were in effect may have the "C" code suffix as part of the part number on the manufacturer's certificate of conformance. Parts manufactured to later revisions cannot have the "C" code suffix. The use of this suffix should be discouraged as it is obsolete.
On the NASM20426, NASM20470, and NAS1097 drawings, the "F" code suffix indicates the option of any finish. This is an engineering notation only. While in an abstract sense, the "F" code is a valid part number call-out, no manufacturer will certify a part with the "F" code suffix as it indicates a variety of finishes. A part can only be certified to the finish that it has been processed to by the manufacturer.
An NASM20426DD and NASM20470DD code rivet (2024-T4 aluminum alloy) without a suffix (A, D, or N) is not a valid part number call-out. These rivets MUST be furnished with an anodize finish per MIL-A-8625, either 'type II, class 1 dichromate seal', 'type II, class 1 clear', or 'type II, class 2 colored'. 2024-T4 aluminum alloy rivets are supplied in a heat-treated form, and are re-heat treated just prior to installation, or are stored in a refrigerated condition after the re-heat treating. The re-heat treating process would break down any chemical surface treatment that was applied, therefore a chemical surface treatment per MIL-DTL-5541 is not acceptable for these rivets.
On the NASM20426 and NASM20470 drawings, there is some ambiguity regarding the finish requirements for code T (titanium-columbium alloy) rivets. No code after the part number indicates chemical surface treatment per MIL-DTL-5541 Class 1A Gold/Yellow. This has led to some to conclude that titanium rivets should be gold chemical film finish per MIL-DTL-5541. This is incorrect. Further down in the examples of part number, the drawing states "For titanium-columbium, no finish required". Titanium solid rivets are normally manufactured and supplied with no finish.
On the NAS1097 drawing, for titanium rivets, no code after the part number indicates "no finish". There are two optional finishes shown. P-Code indicates "Anodize per ISO 8080". V-Code indicates "Ion vapor deposited coating". For a titanium rivet, "no code" after the part number should never be interpreted as chemical surface treatment per MIL-DTL-5541 Class 1A Gold/Yellow.
Measurement of head diameters on countersunk rivets is done to theoretical sharp corners as measured by projection, for example, on an optical comparator. The measurement should not be performed with a Vernier caliper or a micrometer, to the physical size of the head, as this does not yield the intended measurement, or a range of tolerance.