Manufacturers keep trading heavy castings for thin-gauge steel, aluminum and composite panels. The fasteners do not always follow, and the load points are where assembly stalls. Grand View Research values the global industrial fastener market at USD 103.92 billion in 2025, growing at a 5.1 percent annual rate through 2033.
Get the joint wrong and the cost lands twice. Scrap hits the floor now, and claims arrive later. U.S.-based manufacturers paid $30.37 billion in warranty claims during 2025, per Warranty Week’s 23rd Annual Product Warranty Report. OEMs shrink that exposure by specifying the right threaded insert while the panel is still on the screen.
| Fastening Method | Thin-Sheet Suitability | Blind One-Sided Install | Spin-Out Resistance |
|---|---|---|---|
| CSG Sherex Rivet Nuts | Strong in thin sheet, plastics and composites | Yes | High with knurled or hex bodies |
| Weld Nuts | Weak, burn-through and distortion risk | No | High once welded |
| Clinch Nuts | Moderate, needs press access and tonnage | No | Moderate to high |
| Self-Tapping Screws | Weak, strips in thin gauge | Yes | Low |
| Tapped Holes in Sheet | Weak, too little thread engagement | Yes | Low |
Why Thin-Gauge Metal and Composite Assemblies Fail in the Field
Mismatch the fastening method to the gauge and the damage compounds. It starts as scrap and ends as a field failure. Seven failure modes account for most of it.
- Burn-through and distortion. Welding standard nuts to thin-gauge steel or aluminum dumps heat into a panel that cannot absorb it. The sheet warps, and sometimes the arc goes straight through. The part gets scrapped or sent out for grinding and refinishing.
- Too little thread engagement. Tapping directly into sheet metal leaves almost no engaged thread length, so the joint carries a fraction of the bolt’s rated load. Fasteners pull out under modest axial load. Our drill hole size calculator for tapped threads shows how quickly the numbers fall apart in thin stock.
- No access to the back side. Nut-and-bolt assemblies need two hands on two sides. Enclosed frames, tubes and closed sections do not offer that. Design teams then redraw the layout or park the line while an operator reaches in.
- Vibration and spin-out. A fastener with no mechanical lock into the base material turns under cyclic load. Automotive frames, trailers and heavy machinery vibrate every hour they run. The insert spins, the torque spec becomes fiction, and the joint opens up in service.
- Galvanic corrosion at dissimilar-metal joints. A plain steel insert set into an aluminum or carbon fiber panel creates a galvanic couple, and the lighter metal pays for it. Multi-material joining on lightweighting programs makes that pairing routine rather than rare. Specify body material and finish against the base panel, or the joint corrodes from the inside while the exterior coating still looks new.
- Automated feeding and cycle time. Hex bodies resist rotation because the geometry does, which means the punched hex hole and the fastener flats have to agree on every cycle. Automated fastener feeding in a robotic cell adds an orientation step that round bodies skip. Budget that cycle time during process design, not after the cell is quoted.
- Operator fatigue on manual tools. Hand wrenches and uncalibrated mandrels put the load on the operator’s wrist and shoulder across a full shift. Set quality drifts as the shift wears on, and a repetitive strain claim costs more than the proper tool would have.
The Core Sherex Rivet Nut Families
A rivet nut puts a strong, reusable thread into material too thin to tap. Picking the right Sherex body style is what separates a joint that holds from one that spins on the second service call.
The CAL and CAK series cover general manufacturing. Both use a knurled round body that bites into the base material and resists rotation. CAL carries a large flange that spreads clamp load across a wider bearing surface, which keeps the head from pulling through soft or thin panels. CAK uses a small flange for near-flush mounting where the surface has to stay clean.
When shear strength matters more than profile, the CFT and CFW series step up. Both use 360-degree swaging and a thick wall. CFT runs a knurled body, CFW a diamond knurl for extra spin-out resistance in softer materials. Procurement teams sourcing sherex nut rivets for heavy equipment usually land here or on a hex body.
Hex bodies win the torque-out argument outright. The FHK full hex and CAH half hex install into a matching hex hole, so the geometry itself blocks rotation. That makes them the default choice for high-torque blind inserts in frames, brackets and towing structures. Sherex reports that a hex body rivet nut is almost 10 times stronger than a typical knurled round body installed in the same material. The trade-off is real: you have to punch a hex hole, and automated feeders must line the points up every cycle.
The CPB and CPN series use a slotted body. CPB comes pre-bulbed and folds out into an oversized backside footprint, which raises pull-out resistance in plastics and covers a wide grip range. That last point matters on real production parts, where a single part number has to work across single, variable or stacked material thickness.
Securing EV Composites and Brittle Materials Without Delamination
Aerospace and EV programs run heavy on carbon fiber, fiberglass and engineered plastics. Lightweighting targets push those materials into structural positions, and EV battery enclosure fastening is usually where they land first. The materials carry load well and crack badly.
Clinch fasteners and solid rivets push outward against the hole wall during installation. A composite matrix does not forgive that radial stress. The laminate crushes at the bore, and delamination spreads from the hole once the joint sees load.
Sherex blind rivet nuts sidestep the problem. The tool threads onto the insert and pulls the internal threads upward, collapsing the unthreaded shank against the blind side of the panel. The hole diameter itself stays where it started.
Because the set is driven by axial pull instead of radial expansion, the panel keeps its structure and the clamp load spreads across the folded footprint. One operation, one side, a finished machine thread. Work through the rivet nuts and studs range and the broader threaded inserts catalog to match grip range, body material and galvanic corrosion resistance to the laminate you are actually building.
Installation Mechanics and Sherex Setting Tools
A blind insert is only as good as the set. Hand wrenches and improvised mandrels produce loose clamp, stripped internal threads and joints nobody can torque to spec. CSG supplies the pneumatic and hydro-pneumatic installation tools that OEM lines run every shift.
Spin-pull tools thread the fastener onto the mandrel, pull back to collapse the shank, then reverse off. Sherex builds the MS 100 for thin-wall and heavy-duty nuts from 5/16-18 to 1/2-20, and the FLEX-18 for the heavy end at 18,000 pounds of pulling force across 5/16-18 to 3/4-10. Operators stop fighting the tool, and the set repeats.
The bigger decision is pull-to-pressure versus pull-to-stroke. A pull-to-stroke tool travels a fixed distance, so any variation in sheet gauge changes the result. A pull-to-pressure tool reads the resistance of the collapsing fastener and stops at the correct setting force. Sherex ships both, the FLEX-5P for pressure and the FLEX-5S for stroke, each with process monitoring on the cycle. On mixed-gauge assemblies, pressure control is the safer default.
Engineered Supply Chain Consolidation Through CSG
Sourcing the right insert is half the job. Getting it to the right line station on the right day is the other half. Component Solutions Group, a Bufab company, runs vendor-managed inventory, kitting and global sourcing behind the fasteners we supply.
CSG does not manufacture these components. We engineer the specification, manage the flow, and keep stockouts off your board. Operations hold ISO 9001:2015, AS9120 Rev B and ITAR registration, which gives defense, aerospace and medical device customers full traceability on every lot.
Our technical team sizes the insert, the hole, and the tool together, then hands back performance data instead of a catalog page. From there, kitting and assembly covers sorting, containment and light assembly so parts arrive production ready.
How to Move From Assembly Bottlenecks to Reliable Production
The decision splits cleanly. If the panel is thin, the back side is closed, or the substrate is a composite, use a blind rivet nut and pick the body style off the failure mode you keep seeing. If it spins, go hex. If it pulls through, go large flange or pre-bulbed. If the panel is aluminum or carbon fiber, match the body material and finish before you worry about anything else. If the gauge varies station to station, set with pull-to-pressure.
Weld nuts and tapped sheet still have a place, but not under 20 gauge and not against vibration. Match flange, body, finish and tool to the base material and the rework line goes quiet.
Stop treating scrapped panels and stripped threads as a cost of doing business. Submit an RFQ to our OEM team, or request a sample kit and run a trial installation in your own material before you commit a part number.
Frequently Asked Questions (FAQs)
What grip range should I specify for a Sherex rivet nut?
Grip range is published per part number, not per series. Sherex notes that grip range on knurled round bodies is affected by parent material and hole size, and recommends trial installations to confirm it. When material thickness varies across the assembly, the CPB slotted body covers single, variable and stacked thickness in one part number.
How do hex-body rivet nuts prevent spin-out?
A hex body seats in a matching hex hole, so the geometry blocks rotation before the knurl ever has to work. Sherex offers the FHK full hex and the CAH half hex, and reports the hex body as almost 10 times stronger than a typical knurled round body in the same material.
What are the best installation tools for high-volume blind rivet nut assembly?
On a volume line, use a pneumatic or hydro-pneumatic spin-pull tool with process monitoring rather than a hand tool. CSG supplies the Sherex range, including the MS 100 for thin-wall and heavy-duty nuts, the FLEX-5P for pull-to-pressure and the FLEX-5S for pull-to-stroke setting, and the FLEX-18 at 18,000 pounds of pulling force for the heavy end. We size the tool to the insert, the base material and the production volume.
Which rivet nut material prevents galvanic corrosion in aluminum and composite panels?
Match the insert to the panel. Aluminum bodies pair with aluminum panels and keep the galvanic couple small. Steel bodies in aluminum or carbon fiber need the right finish or an isolating sealant, because carbon sits at the cathodic end and drives corrosion in the surrounding metal. Sherex publishes body material and finish per part number, and our engineers confirm the pairing before it goes on the print.
