You are here: What Kinds of Pull Rivet Nuts Exist: Head, Shank, End Structure and Material Choice - CHANRUI
Also referred to as "pull rivet nuts", quite a few types are available on the market, and choosing the wrong kind directly causes nut follow-rotation, looseness or leakage. This article walks through the common types across four dimensions - head shape, shank shape, end structure and material - and offers a selection method, so process and procurement staff can compare and order.
I. By shank form (most important)
| Category | Pre-punched hole | Features and applications |
|---|---|---|
| Cylindrical smooth-shank type | Round hole | The most common, low-priced and simple to machine; suited to general thin plates and positions not subject to large torque |
| Knurled (vertical-rib) type | Round hole | The shank knurl presses into the plate surface, giving torsion resistance and anti-slip grip, suited to repeated assembly/disassembly or positions with some torque requirement |
| Hexagonal or semi-hexagonal type | Hexagonal hole | Six-sided engagement prevents rotation and offers the strongest torsion resistance, commonly used at load-bearing points in automotive and power cabinets, although it demands high hole-punching process requirements |
II. By head form
Flat head (oval-head)After riveting, the head seats on the plate surface with a slight bulge and a large compression area, and is most commonly used on inner and non-appearance surfaces;Countersunk head (flush head) / small countersunkAfter riveting it stays essentially flush with the plate surface, and is used for appearance surfaces, slide-rail mating faces and positions with flatness requirements, which call for a countersunk hole. The head shape must correspond one-to-one with the gun rivet head; mixing them will crush the plate surface or cause poor forming.
III. By end structure: through hole versus blind hole
| Comparison point | Through-hole type (open) | Blind-hole type (closed) |
|---|---|---|
| Structure | The nut is open at both ends, so the screw can pass through | The threaded end is closed, so the screw does not pass through the backside |
| Sealing | Not sealed | Prevents liquid and moisture ingress, and is used for water tanks, piping and outdoor parts |
| Plate-thickness fit | Wide range | Limited by the closed end; choose the plate thickness per the catalog |
| Price | Low in price, most commonly used | Higher in price |
The 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 specifications
Common materials include steel (zinc-plated), aluminum, stainless steel and copper: steel nuts offer high strength at low price and are generally used with cold-rolled plate; aluminum nuts are light and pair well with aluminum profiles; stainless steel is used outdoors, in kitchens/baths and corrosion-resistant applications; copper nuts serve conductivity and special cases. Specifications cover the common M3 to M12, and the plate thickness together with the thread specification determines the exact model - too large will not insert, too small lacks strength. The 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. A four-step selection method
Step one, set the thread specification (the M size of the subsequent screw); step two, check that the plate thickness falls within that specification's riveting thickness range; step three, choose the shank according to load and anti-rotation requirements (smooth for ordinary round holes, knurled for torque, hexagonal for high requirements); step four, choose the head shape and through/blind hole by appearance and sealing requirements, then choose the nut material by workpiece material. When unsure, send the 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 feed channel by specification).
FAQ on Rivet Nut Type Selection
Rivet Nut Type Selection FAQ
Round-hole smooth nuts offer limited torsion resistance; switch to a knurled or hexagonal type with the corresponding pre-drilled hole, and confirm that the pull-riveting stroke reaches position and the plate surface is seated.
Prioritize stainless-steel material and a blind-hole closed type, paired with a sealing washer, to keep rainwater from seeping along the threads.
Replacing the screw and rivet head switches the specification and head shape; round and hexagonal holes use different feed positioning, so list all the types to the manufacturer for evaluation when selecting automatic equipment.
An overly deep countersink depresses the rivet point, while 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 us coupons and we will decide for you
We recommend the type and machine model by plate thickness, hole diameter and load scenario, with on-site trial riveting available; consultation hotline +86 13268883882.
VI. Common procurement and usage mistakes
First, looking only at the 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 cover 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, buying equipment and nuts separately without matching: it is recommended to have the same party confirm the 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, we recommend requesting nut samples of the corresponding type per the actual plate thickness and hole diameter, completing first-article verification together with the on-site trial, and confirming that forming, torque and appearance pass before fixing the bulk specification.
Recommended reading:Uses, Working Principle and Common Problems · Application in Sheet Metal Processing · Automatic Rivet Nut Gun
Previous 
