Industrial vs aerospace fasteners

A few families in the SpecLok catalog carry an Industrial tag. They are good fasteners built to their manufacturer's own specifications, not to an aerospace standard. Here is what that difference means and when it matters.

Which families are tagged

Huck BOM, Huck Magna-Lok and Huck Magna-Grip are sold in Howmet's industrial product lines; the BOM brochure lists uses such as military vehicles and equipment, auto suspensions, amusement park rides, rail car assembly and storage racks [1]. Avdel describes its lockbolts as mostly used in automotive, HGV and transportation, machinery and construction markets, and lists commercial vehicles, railway, bridge building and mining among Avdelok applications [2]. Their strengths are published in the manufacturer brochures, and SpecLok shows those values with the brochure cited.

1. Spec control

An aerospace standard part is defined by a public specification. FAA AC 20-62E describes a standard part as one "manufactured in complete compliance with an established U.S. Government or industry-accepted specification, which includes design, manufacturing, and uniform identification requirements," with NAS, AN, SAE, AS and MS as examples [3]; 14 CFR 21.9(a)(3) refers to a standard part "manufactured in compliance with a government or established industry specification" [4]. The specification fixes the part's dimensions, tolerances, material and finish (for example, the MS20470 sheet sets rivet dimensions with tolerances and the permitted material codes) [5]. An industrial fastener's design, tolerances and finish are whatever its manufacturer's catalog states, and can change with that catalog.

2. Material certs and lot traceability

AC 20-62E covers "the quality, eligibility and traceability of aeronautical parts and materials" and puts the burden on the installer: "it is the installer's responsibility to request documentation establishing traceability" [3]. Aerospace distributors supply that documentation with the part. For an industrial fastener, ask what certification and lot traceability the supplier can provide before you rely on it.

3. Quality system

AS9100D is the quality management standard for aviation, space and defense organizations: it includes ISO 9001:2015 and adds aerospace-specific requirements [6]. An industrial product line may be made under a different quality system, so check which certifications the manufacturer and distributor hold.

4. Qualification and published allowables

MIL-HDBK-5 (now MMPDS) publishes design allowables for mechanically fastened joints, including solid rivets, blind fasteners, swaged-collar and threaded fasteners (MIL-HDBK-5J ch. 8) [7], and AC 43.13-1B notes that "design allowables for riveted assemblies are specified in MIL-HDBK-5" [8]. Industrial fasteners have no such handbook allowables: their brochures give minimum installed strengths from the manufacturer's own testing [1][2]. That is useful data, but it is not a design allowable.

When an industrial fastener is a reasonable choice

Where no aircraft part is involved, such as ground support equipment, tooling and fixtures, test rigs, and vehicle or industrial structure, the aeronautical-part guidance above (AC 20-62E's scope [3]) doesn't apply, and an industrial fastener with a published datasheet is often the practical, economical choice. Non-flight and secondary uses should still be sized from the manufacturer's published values with your own margins.

For experimental amateur-built aircraft (14 CFR 21.191(g)) [9], FAA AC 20-27G says standard aircraft hardware "may be procured on the open market", recommends "material of established quality (for example, materials produced under a military specification, SAE, or AN)", and says builders "should not use materials of unknown identity or quality" [10]. An industrial fastener with a manufacturer datasheet is an identified part, but the AC's recommendation points to spec-controlled hardware; the builder makes and owns that call.

For type-certificated aircraft structure, use the part the approved data calls for. SpecLok ranks industrial families below aerospace-spec families in the selector for this reason, and tags them wherever they appear.