Buying aerospace fasteners: the RFQ line, the minimum order, new surplus stock and the paper behind the lot
Bolts, screws, nuts, washers, rivets and collars are the cheapest lines on most parts lists and the ones that go wrong most quietly: a dropped suffix letter, a pack of 100 when you needed 12, a new-surplus bag with no manufacturer on the paper. This guide covers the purchase itself: the line, quantities and minimums, what "NS" means for hardware, lots and certificates, and suspect fasteners.
What AN, MS and NAS numbers mean, and why a standard bolt normally ships with a certificate of conformance rather than an 8130-3, is covered in our guide to standard aircraft hardware (AN, MS, NAS). This page assumes that background and goes on from it.
Why fasteners are bought differently
Three things set hardware apart from rotables and line-replaceable units:
- No serial number. A fastener's identity is its part number, its markings, its lot and the paper that travels with the bag. Lose the bag or the lot label and you cannot get the identity back.
- Low unit value, high line count. The cost of a hardware line is usually set by the minimum order, the pack size and the certificate, not by the unit price.
- Many sources for one number. A standard part can be made by any manufacturer that meets its specification, and it is offered new from stock and new surplus from someone's overstock. The number is identical; the paper behind it is not.
In supplier quotes we received between June and September 2026, fasteners (bolts, screws, nuts, washers and rivets, matched by line description) made up 27,331 priced offer lines covering 2,601 distinct part numbers: about 23% of all offer lines, more than any other category we break out. Hardware is not a side issue on a parts list; it is nearly a quarter of the traffic.
Specifying the line: the full number, then everything else
The single most useful rule: copy the part number from the drawing, IPC or repair data character for character, including the dash number and every letter. On standard hardware the letters carry material, finish, drilling or a locking feature, so a shortened number is a different part. Decode a number only against its own standard sheet; the conventions differ from standard to standard.
Things that belong on a fastener line, and why:
| Field | What to write | Why it matters |
|---|---|---|
| Part number | Full number with dash and suffix, e.g. MS21042L3, NAS1149F0363P | A seller matching to stock may quote the nearest number they have. Only the exact string can be checked against the offer. |
| Description | Short: "nut, self-locking", "washer, flat" | A cross-check that catches a typo in the number. It never replaces the number. |
| Quantity and unit | 12 EA, or 1 PK of 100 if you buy by the pack | Hardware is sold by the each and by the pack. Say which one your quantity means. |
| Condition | NE, or "NE, NS acceptable" | Surplus stock is common in hardware (see below). Decide in advance whether you accept it. |
| Document | "Mfr CoC to standard, lot no." or your procedure's requirement | If it is not on the line, a lower price may arrive without it. |
| Alternates | "None", or the specific number your data allows | Leave it blank and some sellers will substitute a superseding or "equivalent" number. Accept only what your approved data permits. |
| Pack / lot preference | "Original manufacturer packaging, single lot preferred" | Split packs and mixed lots make receiving and trace harder (see below). |
Airframer standards are not AN/MS/NAS. Numbers from an airframe manufacturer's own standards, such as the BACB30 bolt family, look like standard hardware but are specified by that manufacturer's documents rather than a published NAS or MS sheet. Before you ask for an "equivalent" NAS number, check with your engineering what your data allows.
Supersessions are one-way questions. Some AN numbers have been superseded by MS numbers; a few verified examples, with the FAA's wording, are in the standard hardware guide. Whether you may install the newer number in place of the one your IPC calls out is an engineering decision, not a buyer's. How to state it on the RFQ is covered in alternate and interchangeable part numbers.
Quantities, minimum orders, packs and price breaks
Hardware pricing has three layers, and a quote that shows only one of them is not comparable with the next.
- Minimum order (MOQ or minimum line value). Many sellers will not break below a quantity or a line value. On a line worth a few dollars the minimum is effectively the price. Ask for the minimum on every line, not in a cover note.
- Pack quantity. Stock often sits in the manufacturer's bags of a fixed count. Taking the whole bag can cost less than a split, and it keeps the manufacturer's label and lot number with the parts, which AC 20-154A (paragraph 7.6.12) asks receiving systems to preserve "whenever possible" until the parts are installed or sold.
- Price breaks. Unit price usually falls at quantity steps. If your usage is steady, ask for the price at your quantity and at the next break; buying the break may cost little more than the minimum.
A minimum order was stated on 77.5% of fastener offer lines we received between June and September 2026, against 68.1% of lines for parts outside the fastener, seal, valve, pump and engine hot-section categories. On hardware, expect the minimum to be part of the answer, and compare offers at the quantity you will actually be billed for.
Say on the RFQ whether a larger pack is acceptable ("pack quantity acceptable up to 100"), and keep hardware on the same RFQ as the rest of the list: ten washers alone attract a minimum, on a longer request they are one more line. More in the true cost of an aircraft part.
NE or NS: what new surplus means for hardware
Both codes mean unused. NE (new) usually means stock bought from the manufacturer or through its distribution. NS (new surplus) means unused parts that passed through another owner first: an operator's or MRO's overstock, a manufacturer's excess, or released military stock. The full list of codes is in our guide to condition codes.
New surplus is far more common in hardware than elsewhere. Of the fastener offer lines we received between June and September 2026, 40.2% were NS and 53.6% NE; for parts outside the categories we break out separately, NS was 23.0%. Seals and O-rings sat between the two at 28.3%.
That makes sense: hardware is bought in packs and used in ones, so every stores department ends up with surplus bags. The FAA's view of surplus is in AC 20-62E. It defines surplus parts as released "by the military, manufacturers, owners/operators, repair facilities, or any other parts supplier" and says they "should show traceability to an FAA-approved manufacturing procedure." It also warns that "the storage time, storage conditions, or shelf life of surplus parts and materials are not usually known," and that items advertised as "unused" or "like-new" "should be carefully evaluated before they are purchased."
For NS hardware, that translates into a short list of questions before the PO:
- Is the part in the original manufacturer packaging, with the manufacturer's label and lot number?
- Which manufacturer made it, and is the manufacturer's CoC or test report available, not only the seller's own statement?
- Where did it come from (the trace), and is the quantity offered a single lot?
- For plated or coated parts, is the finish intact? AC 21-29D lists the "absence of required plating" and corrosion among irregularities to evaluate on receipt.
NS in an unbroken manufacturer bag with a manufacturer's CoC can be a good buy; NS in a plain bag with only a seller's label is the weakest paper you will be offered.
Certificates and lot traceability
For a standard part, the document your receiving inspection normally expects is a certificate of conformity naming the standard, the manufacturer and the lot. What that certificate should contain, and when an 8130-3 is required instead, is set out in the standard hardware guide. On the purchase side, three points matter:
- Manufacturer's CoC or distributor's CoC. They are different statements. A distributor certifies what it bought and shipped; a manufacturer certifies what it made. Ask on the line which one you will receive, and whether the manufacturer's paper sits behind the distributor's.
- An 8130-3 costs you offers. If your procedures demand one for hardware, write it on the line; fewer sellers can supply it.
- Certificate duplication for split quantities. When one bulk certificate covers a lot that is split between several orders, each shipment needs its own copy. AC 20-154A's sample receiving checklist asks whether there are "procedures for duplicating certificate received with bulk shipment of the same type part." Ask the seller how a copy is issued and who signs it.
On 54.1% of fastener offer lines we received between June and September 2026, no certificate was stated at all. An 8130-3 was named on 9.9% and an EASA Form 1 on 3.5% (dual releases count in both); a trace source was stated on 42.7%. A quote that says nothing about paper does not mean the part has none, but it does mean you should ask before you compare prices.
Mixed lots and split packs
A lot, in the definition used by the US Fastener Quality Act, is "a quantity of fasteners of one part number fabricated by the same production process from the same coil or heat number of metal as provided by the metal manufacturer." Test results and certificates attach to a lot. A quantity drawn from three lots needs three sets of paper, and receiving has to tell which pieces belong to which.
- Ask for a single lot per line where your procedures need it, or ask the seller to state how many lots make up the quantity.
- If lots are mixed, ask that each lot arrive bagged and labeled separately with its own certificate.
- A split pack (a quantity counted out of a larger manufacturer bag) loses the manufacturer's label. Ask how the seller carries the lot number and manufacturer onto the new bag and onto the certificate copy.
Counterfeit and suspect fasteners: the warning signs
Suspect small parts are a live problem because non-serialized items are easy to relabel. The FAA's guidance on detecting and reporting suspected unapproved parts, AC 21-29D, lists situations that "may raise questions" when dealing with an unfamiliar seller:
- "A quoted or advertised price that is significantly lower than the price quoted by other distributors and/or suppliers of the same part."
- "A delivery schedule that is significantly shorter than that of other distributors and/or suppliers (when the stock of a like item is exhausted)."
- Quotes from unidentified sellers "that imply an unlimited supply of parts."
- An "inability to provide substantiating documentation" for the part.
The circular adds that these signs "are not conclusive." For hardware, it recommends that receiving inspection "conduct random sampling of standard hardware packaged in large quantities," and notes that standard parts "are not required to be produced under FAA approval; therefore it is incumbent upon the installer to determine that the part conforms." Suspect parts are reported to the FAA on Form 8120-11 through the FAA Hotline. What to check when the box arrives is covered in receiving inspection for aircraft parts.
Do not lean on the Fastener Quality Act. The FQA (15 U.S.C. chapter 80) is often cited in fastener buying, but its definition of "fastener" is narrow. It covers threaded metal fasteners of 1/4 inch (6 mm) nominal diameter or larger, and load-indicating washers, that are through-hardened and grade identification marked (or represented as meeting a standard that calls for it). It excludes, among others, fasteners "specifically manufactured for use on an aircraft if the quality and suitability of those fasteners for that use has been approved" by the FAA or a foreign airworthiness authority, fasteners made under a fastener quality assurance system, fasteners made to a proprietary standard, and replacement parts sold in packages of 75 or fewer. Rivets, plain washers and small screws are outside it by definition. For aircraft hardware, the controls that protect you are your purchase order, your receiving inspection and the FAA guidance above.
Stocking distributor or broker?
The choice depends on what you are buying and what paper you need. The wider map of sourcing channels is in where to buy aircraft parts.
| Situation | Usually better fit | What to confirm |
|---|---|---|
| Current standard part, steady usage, manufacturer's CoC required | Stocking distributor buying from manufacturers | Which manufacturers it carries; manufacturer's paper behind its own CoC; pack sizes and breaks. |
| Obsolete, low-demand or long-lead number | Broker or surplus source | Trace and manufacturer; condition (NE or NS); original packaging; lot count. |
| Very small quantity, urgent | Whoever has it on the shelf with acceptable paper | Minimum order and line charges; shipping point; whether the certificate is included in the price. |
| Mixed list: hardware plus components | One source quoting the whole list | That each hardware line still carries its own condition and document, not a blanket note. |
Buyer's checklist for a fastener order
| # | Check | Before RFQ | Before PO | On receipt |
|---|---|---|---|---|
| 1 | Full part number, dash and suffix letters, copied from approved data | ✓ | ✓ matches the quote | ✓ matches bag and paper |
| 2 | Alternates stated per line (none, or the number your data permits) | ✓ | ✓ no silent substitute | ✓ |
| 3 | Condition: NE only, or NS acceptable | ✓ | ✓ | |
| 4 | Document per line: manufacturer's CoC, distributor's CoC or 8130-3 | ✓ | ✓ confirmed in writing | ✓ present and signed |
| 5 | Manufacturer named | ✓ | ✓ same on bag and CoC | |
| 6 | Lot: single lot, or lot count stated; lots bagged separately | ✓ | ✓ | ✓ lot on bag = lot on CoC |
| 7 | Original manufacturer packaging, or how a split pack is relabeled | ✓ | ✓ | ✓ intact, not altered |
| 8 | Minimum order, pack quantity and next price break | ✓ ask | ✓ compare at billed quantity | |
| 9 | Price and lead time out of line with other quotes | ✓ ask why | ||
| 10 | Finish, plating and markings; random sample of large quantities | ✓ |
The rest of the request, from header to delivery address, is covered in how to write an aircraft parts RFQ.
Send your hardware lines with the rest of the list
Send your RFQ to [email protected] in the file you already have — Excel, PDF, a scan or the email body, five lines or five hundred — with the full part number, the condition you accept and the document you need on each fastener line. Your inquiry will be reviewed by a specialist within one business day.
In our client portal, RFQ Radar, every quoted line shows condition, certificates, quantity, unit price in USD, lead time in days and minimum order, and you can filter by condition, so NE and NS offers for the same number sit side by side. A purchase order there has a "certificate needed" tick on each line.
Before you buy, check what certificates and trace come with each part. Aircraft on ground? See our 24/7 AOG desk.
Sources
- AC 21-29D Change 1, Detecting and Reporting Suspected Unapproved Parts — FAA, 12 July 2016, Change 1 of 13 February 2018 (paragraphs 5.2.2, 5.3.6, 5.3.7, 6.2 and Appendix B.1.10).
- AC 20-62E Change 1, Eligibility, Quality, and Identification of Aeronautical Replacement Parts — FAA, Change 1 of 14 September 2018 (paragraphs 6.h and 11, surplus).
- AC 20-154A, Guide for Developing a Receiving Inspection System for Aircraft Parts and Materials — FAA, 3 July 2024 (paragraph 7.6.12 and the sample checklist, bulk quantities).
- 15 U.S.C. § 5402, Definitions (Fastener Quality Act) — Legal Information Institute, Cornell Law School ("fastener" and "lot").
- 15 U.S.C. chapter 80, Fasteners — Legal Information Institute, Cornell Law School (section listing and § 5411b, applicability).