Rivet nuts
Blind threaded rivet-nut mechanisms, grip and hole geometry, product variants, and the limits of catalogue performance data.
Tags: components, fasteners, rivet-nuts, threaded-inserts
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Böllhoff's hexagonal steel RIVKLE 233 41 060 030 lists M6, 0.5–3.0 mm grip, 15.7 mm body length and a 9.0 +0.1/0 mm hexagonal hole across flats. GESIPA's half-hexagonal A2 1455460 also lists M6, but has 15.5 mm body length and an SW9 +0.1 hole field. Use the exact mounting drawing, grip range and setting conditions for each product. catalogue's steel flat-head hexagonal open table, p. 17, article-specific technical specifications.
Scope and mechanism
A blind rivet nut installs an internal thread in a thin host with setting access from one side. GESIPA, Blind rivet nuts.
RIVKLE setting forms a bead from the shank behind the sheet. The head and bead grip opposite faces. Böllhoff, RIVKLE method and principle.
Use the exact product’s installation and performance evidence for the actual host.
Geometry and product identity
| Feature | Distinction |
|---|---|
| Head | GESIPA describes a flat head as providing a large contact area; a small head reduces protrusion. A countersunk head corresponds to a countersunk hole. Those forms should not share an assumed seating geometry. |
| Shank | Round, knurled, hexagonal and square are distinct GESIPA options. A polygonal body is not merely a round body with a different nominal diameter. |
| Host material | GESIPA offers steel, aluminium and stainless-steel nuts. The insert material designation does not identify the host-sheet material. |
The head, shank and material descriptions above come from GESIPA, construction of a blind rivet nut.
Böllhoff separately lists smooth round, knurled round, hexagonal and partial-hexagonal RIVKLE shanks. It identifies hexagonal geometry as resisting rotation. Its standard range includes open and closed ends; the closed version adds protection against dirt and moisture. A closed end alone is not evidence of a qualified seal at the head-to-sheet interface: Böllhoff identifies Seal Ring as a separate product technology. Böllhoff, Standard and Seal Ring variants
Grip, hole and clearance dimensions
Böllhoff's catalogue legend defines grip range as the total thickness retained, including a multilayer workpiece. It distinguishes thread size, overall length, head size and hole geometry. A round hole uses diameter; a hexagonal hole uses width across flats. Setting stroke is the change in overall length. The listed blind-side projection is a clearance quantity, explicitly unsuitable as a quality-control criterion. RIVKLE catalogue, p. 13
The following examples retain each source's dimensions and terminology; they are not a cross-brand substitution table.
| Named part and source | Body, head and end | Selected dimensions in that source |
|---|---|---|
Böllhoff RIVKLE 233 41 060 030 |
Steel, hexagonal, flat head, open | M6; grip 0.5–3.0 mm; length 15.7 mm; head diameter 12.9 mm; hexagonal hole H = 9.0 +0.1/0 mm across flats. |
GESIPA article 1455460 |
Stainless steel A2, material No. 1.4567; half-hexagonal, small head | M6; body length 15.5 mm; head diameter 10.40 mm; thread length 8.00 mm. Hole field is published as SW9 + 0,1. |
The RIVKLE row is from the catalogue's steel flat-head hexagonal open table, p. 17. The GESIPA row is from its article-specific technical specifications. The latter is HTML product data, not an inspected controlled drawing; its SW hole field must not be read as a round drill diameter. Neither row establishes interchangeability, finished-hole process capability or an accepted joint load.
Setting, rotation and failure terminology
Sherex's catalogue distinguishes rivet-nut test results by failure mode and fixture:
| Term in Sherex's testing methods | What it measures |
|---|---|
| Spin out | Torque that makes the installed nut rotate in its hole. |
| Torque out | Thread-stripping torque with the nut head trapped between a nonrotating mating part and the base panel. This fixture suppresses spin-out. |
| Pull out | Axial failure through thread extraction, or through base-material distortion allowing the complete nut to pull through. |
| Suggested assembly torque | An assembly recommendation associated with Class 8.8/Grade 5 hardware, rather than a setting-force specification. |
Sherex also identifies cross-threading, corrosion-induced binding and locking-screw prevailing torque exceeding spin-out resistance as possible spin-out causes. It warns that friction, finish and washers affect torque and calls for application testing. Thus antirotation geometry is only one part of the joint definition; thread-stripping torque cannot substitute for rotation resistance. Sherex, C-RN 5/2017, printed p. 47 / PDF p. 49
Reading catalogue performance conditions
Masterfix's October 2024 catalogue describes typical results from representative samples, not guaranteed performance of every application:
- Applied-torque testing uses a mating test screw and a steel top plate restrained from rotating. Its torque column is the maximum recommended torque applied to the mating screw.
- Pull-out testing uses steel plates at the particular nut's maximum grip thickness.
- Single-shear testing uses hardened steel plates at maximum grip; the reported strength concerns the nut and excludes the mating screw.
The catalogue states that the application's material or screw may be weaker and recommends testing the actual joint. Masterfix, printed p. 47 / PDF p. 24
Its 23-CO series, for example, is steel, zinc plated, open ended and cylindrical headed. That description does not identify a stainless, closed-end or hex-body equivalent. The same catalogue distinguishes the EPDM MFX Rubnut, which deforms during mating-screw tightening, from tool-set metal rivet nuts. Masterfix, printed pp. 48–49 / PDF p. 25
Application-specific coverage limits
Explanatory synthesis: the cited dimensions describe named combinations of thread, head, body, end form and material with a particular grip range and mounting-hole geometry. They do not establish interchangeability with other parts or a complete specification for an unspecified joint. RIVKLE catalogue, steel hexagonal examples, p. 17
Masterfix's installed-nut results cover the stated mating-screw, plate and maximum-grip test conditions. They do not establish performance for a different host material, retained thickness or screw pairing. Application-specific setting controls, finished-hole quality and accepted service loads are outside the evidence presented here. Masterfix, printed p. 47 / PDF p. 24
No full ISO, DIN or aerospace standard was reviewed for this draft. Catalogue references to standards do not establish compliance of an unspecified joint.
Source editions and review limits
Review and retrieval date: 2026-10-30 PDT (America/Los_Angeles). This is distinct from publication date. Only the cited sections and product rows support this draft; neither complete catalogue coverage nor a current controlled engineering drawing is claimed.
- Böllhoff RIVKLE, Blind rivet nuts and studs: printed document code
2307/21-V1-EN (BOF) 99900000027/00, back cover / PDF p. 68. Cited geometry and dimensional pages were visually inspected. Exact publication day is unstated. Catalogue and document identifier - Masterfix, Blind Rivets, Rivet Nuts & Tooling Catalogue: back cover identifies
©2024and10.24; cited printed pp. 47–49 and the back cover were visually inspected. Exact publication day is unstated. Catalogue, PDF p. 41 - Sherex rivet-nut catalogue: printed code
C-RN 5/2017; testing-method page and back cover were visually inspected. This older edition supports terminology only, not current availability or current application values. Catalogue, PDF p. 56 - Böllhoff and GESIPA HTML pages: revision/publication dates are unstated. Their retrieval date does not create a drawing revision. GESIPA's displayed torque and thread-breaking-force numbers are not reproduced because the inspected product page does not provide their full test conditions.
Related reference
Hardware and component references provides adjacent process context; it does not qualify the products or assemblies discussed here.