Why “Inconel 718” Is Not a Complete Fastener Specification
Buying Alloy 718 fasteners? This guide explains how to specify the final heat-treatment condition, finished-part requirements and inspection documents before requesting a quote.
Start with a complete enquiry
Consider this illustrative enquiry: “Please quote 200 Inconel 718 hex bolts, M12 × 60, with a material certificate.” It gives the supplier a quantity, an alloy name and a nominal size. It leaves the final heat-treatment condition, complete part geometry and required inspection documents unresolved. A supplier can respond to that enquiry, but the buyer still needs to establish what the quotation actually includes.
With Alloy 718, the final condition matters
Special Metals identifies Alloy 718 as UNS N07718 and describes it as an age-hardenable alloy. Its technical bulletin explains how solution treatment and precipitation hardening develop the material’s properties, with different treatment routes producing different performance characteristics. For a buyer, this creates a specific question: what condition must the finished fastener be supplied in? For example, solution-treated material and solution-treated-and-aged material can carry the same alloy designation. The designation alone does not establish that they meet the same purchase requirements. Use the final condition specified in the approved drawing or its referenced material specification. If that information is missing, obtain clarification from the responsible engineering team. A supplier’s standard offering should not silently fill the gap. Source: Special Metals, INCONEL alloy 718 technical bulletin (SMC-045, September 2007), pages 1–3. https://www.specialmetals.com/documents/technical-bulletins/inconel/inconel-alloy-718.pdf
What does “ASTM B637” add?
Adding a specification reference makes the enquiry more precise, provided everyone understands its scope. ASTM B637 covers specified nickel-alloy rod, bar, forgings and forging stock for moderate or high-temperature service. It addresses material requirements, including treatment and testing. It does not provide a complete dimensional definition for a finished hex bolt. Where B637 is required, identify the applicable edition and material requirements alongside the finished-part drawing. The quotation should make clear how both will be met. This also helps when reviewing documents: a report for the starting material and an inspection record for the finished fastener describe different stages of supply. Source: ASTM International, ASTM B637 official scope. https://store.astm.org/b0637-26.html
Turn the missing information into a usable enquiry
For the example above, these are the documents and confirmations worth collecting. This is a purchasing aid; it is not a list of mandatory clauses for every Alloy 718 order.
- Final material condition — Check the approved drawing and referenced material specification. The quotation should confirm the required condition and supporting records.
- Finished dimensions and threads — Check the controlled part drawing and revision. The quotation should confirm the drawing revision and any proposed deviations.
- Inspection and documentation — Check the purchase requirements and quality-document instructions. The quotation should confirm the included reports, certificate type and the link to the delivered heat or lot.
Prepare your BYBOLT enquiry
If the drawing already contains the dimensions, send it directly. There is no need to retype every measurement. Add the quantity, requested delivery date and any requirements held outside the drawing. Likewise, replace a broad request for “a material certificate” with the document requirements that apply to the order. Ask the supplier to identify what is included and how those records correspond to the delivered parts. For a BYBOLT enquiry, send the drawing package and purchasing requirements together. BYBOLT can review them with its manufacturing partners and confirm the proposed supply and documentation scope during quotation.