You are here: What Types of Pull Rivet Nuts Are There: Head, Shank, End Structure, Material Selection - BISUDI
Also called "pull rivet nuts", there are quite a few types on the market, and choosing the wrong type directly causes nut follow-rotation, looseness or leakage. This article explains the common types across four dimensions - head shape, shank shape, end structure and material - and gives a selection method, so process and procurement staff can compare and order.
I. By shank shape (most critical)
| Type | Pre-drilled Hole | Features and Uses |
|---|---|---|
| Cylindrical smooth type | Round hole | Most common, low price, simple machining; suitable for general thin plates and positions not subject to large torque |
| Knurled (vertical rib) type | Round hole | The shank knurl is pressed into the plate surface, torsion-resistant and anti-slip, suitable for repeated assembly/disassembly or positions with some torque requirement |
| Hexagonal/semi-hexagonal type | Hexagonal hole | Six-sided engagement prevents rotation with the strongest torsion resistance, commonly used at load-bearing points in automotive and power cabinets, with high hole-punching process requirements |
II. By head shape
Flat head (oval head)After riveting the head seats on the plate surface with a slight bulge and a large compression area, most commonly used on inner and non-appearance surfaces;Countersunk head (flush head)/small countersunkAfter riveting it is essentially flush with the plate surface, used for appearance surfaces, slide-rail mating faces and positions with flatness requirements, requiring a countersunk hole. The head shape must correspond one-to-one with the gun rivet head; mixing will crush the plate surface or cause poor forming.
III. By end structure: through hole and blind hole
| Comparison Item | Through-hole Type (open) | Blind-hole Type (closed) |
|---|---|---|
| Structure | The nut is open at both ends, the screw can pass through | The threaded end is closed, the screw does not pass through the backside |
| Sealing | Not sealed | Prevents liquid and moisture ingress, used for water tanks, piping and outdoor parts |
| Plate thickness fit | Wide range | Limited by the closed end, choose plate thickness per catalog |
| Price | Low, most commonly used | Higher |
Operation differences and processing requirements for through and blind holes are detailed inThrough-hole and Blind-hole Rivet Nut Operation Points。
IV. By material and specification
Common materials are steel (zinc-plated), aluminum, stainless steel and copper: steel nuts have high strength and low price, generally used with cold-rolled plate; aluminum nuts are light and compatible with aluminum profiles; stainless steel is used outdoors, in kitchens/baths and corrosion-resistant applications; copper nuts are used for conductivity and special cases. Specifications cover the common M3 to M12, and plate thickness together with thread specification determines the exact model - too large will not insert, too small lacks strength. Material choice must also consider the subsequent screw and service environment: steel nuts with steel screws, stainless nuts for anti-corrosion positions, copper nuts conduct well but cost more; for positions under long-term load or repeated assembly/disassembly, prioritize hexagonal or extended nuts under the same specification for longer thread engagement and better life.
V. Four-step selection method
Step one, set the thread specification (what M size the subsequent screw is); step two, check plate thickness falls within that specification's riveting thickness range; step three, choose the shank by load and anti-rotation requirements (smooth for ordinary round holes, knurled for torque, hexagonal for high requirements); step four, choose head shape and through/blind hole by appearance and sealing requirements, then choose nut material by workpiece material. When unsure, send plate thickness, hole diameter and usage scenario to the manufacturer, or directly send coupons for trial riveting. Equipment specification compatibility can be referenced inCan Automatic Riveting Machines Use Rivets of Any Specification(rivet nuts likewise change screw and channel by specification).
Type Selection FAQ
Type Selection FAQ
Round-hole smooth nuts have limited torsion resistance; switch to knurled or hexagonal type with the corresponding pre-drilled hole, and confirm the pull-riveting stroke reaches position and the plate surface is seated.
Prioritize stainless steel material and blind-hole closed type, paired with a sealing washer, to prevent rainwater seeping along the threads.
Replacing the screw and rivet head switches specification and head shape; round and hexagonal holes have different feed positioning, so list all types to the manufacturer for evaluation when selecting automatic equipment.
An overly deep countersink depresses the rivet point, an overly shallow one leaves the head protruding; the punching die must be machined to the nut catalog dimensions and undergo first-article inspection.
Not sure which rivet nut to choose? Send coupons and we will decide for you
Recommending type and machine model by plate thickness, hole diameter and load scenario, on-site trial riveting available, consultation hotline +86 13556668682.
VI. Common mistakes in procurement and use
First, looking only at nut unit price: poor-quality nuts have unstable dimensions and many burrs, causing jamming and abnormal screw wear, and the material money saved is not enough to pay for line stoppage; second, casually mixing specifications: mixing nuts from different manufacturers and head shapes at the same station causes problems in both feeding and forming, so fix the supplier and model; third, using smooth nuts at high-torque positions: where knurled or hexagonal should be used, smooth nuts follow rotation and can only be reworked; fourth, purchasing equipment and nuts separately without matching: it is recommended to have the same party confirm equipment, nut specifications and pre-drilled hole process as a whole; fifth, inventory not separated by specification with loose materials mixed and only sorted before loading, which both delays the cycle and easily causes specification errors.
Yes, it is recommended to request nut samples of the corresponding type per actual plate thickness and hole diameter, complete first-article verification together with the on-site trial, and confirm forming, torque and appearance pass before fixing the bulk specification.
Further reading:Uses, Working Principle and Common Problems · Application in Sheet Metal Processing · Automatic Rivet Nut Gun
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