Semi-tubular rivets are among the most widely used permanent mechanical fasteners in modern manufacturing. If you’re sourcing fasteners for an assembly line, replacing an outdated joining method, or specifying components for a new product design, understanding what semi-tubular rivets are—and how to select the right one—can save you thousands in tooling costs and production downtime.
This guide covers everything procurement engineers and product designers need to know: how semi-tubular rivets work, the types available, which industries rely on them, and how to size them correctly for your application.
What Are Semi-Tubular Rivets?
A semi-tubular rivet is a one-piece cylindrical fastener with a formed head on one end and a shallow hole (cavity) drilled into the opposite end—the tail. This partial hole typically extends less than 112% of the rivet’s mean body diameter, which is the defining characteristic that separates a semi-tubular rivet from a fully tubular (hollow) rivet.
During installation, the hollow tail rolls outward and clinches against the workpiece, forming a permanent mechanical joint. Because the material at the tail is thinner and pre-shaped to deform in a controlled manner, the force required to set a semi-tubular rivet is roughly one-quarter of what a comparable solid rivet demands. That single engineering detail—reduced setting force—drives nearly every advantage these fasteners offer in high-volume production.
Semi-tubular rivets are also called tubular rivets or hollow-end rivets in different regional markets. They are manufactured by cold heading (cold forming) from wire stock, then the cavity is punched into the tail in a secondary operation.
Semi-Tubular Rivets vs. Solid Rivets: Key Differences
Buyers often ask whether they should specify solid rivets or semi-tubular rivets. The choice comes down to installation mechanics and joint requirements:
| Feature | Semi-Tubular Rivet | Solid Rivet |
|---|---|---|
| Setting force | ~25% of solid rivet | Full force required |
| Deformation zone | Tail only (rolls outward) | Both head and tail expand |
| Tooling cost | Lower—lighter equipment sufficient | Higher—requires heavy presses or guns |
| Joint strength | High for light-to-medium duty | Maximum shear and tensile strength |
| Cycle time | Faster (≈0.3 seconds per rivet on impact machines) | Slower |
| Pivot joints | Excellent—tail swelling doesn’t lock the joint | Not suitable |
| Material cost | Lower—less raw material per rivet | Higher |
For most light-to-medium-duty assemblies, semi-tubular rivets deliver equivalent reliability at lower total installed cost. Solid rivets remain the better choice only where extreme shear loads or safety-critical aerospace joints demand a fully solid cross-section.
Types of Semi-Tubular Rivets by Head Style
The head style determines how the rivet sits against the workpiece surface and how much bearing area it provides. Choosing the correct head style affects both joint strength and finished appearance.
Oval Head (Round Head)
The most common general-purpose head style. The domed profile provides a large bearing surface and good pull-through resistance. Oval head semi-tubular rivets are the default choice for industrial assemblies where appearance is secondary to performance—brake linings, HVAC ductwork, ladder rungs, and electrical enclosures.
Truss Head
A wider, lower-profile dome that spreads load over a larger area than an oval head. Truss head rivets are preferred when fastening thin or soft materials that might otherwise pull through under load. They also deliver a cleaner finished appearance, making them popular in consumer products, automotive trim, and electronics housings.
Flat Head
A completely flat top surface that sits flush with or slightly above the workpiece. Flat head semi-tubular rivets are used where a low profile is needed but a countersunk hole isn’t practical—common in nameplates, hinges, and light sheet-metal assemblies.
Countersunk Head (100° or 90°)
The head is conical and designed to sit flush within a countersunk hole in the workpiece. This produces a smooth, aerodynamic surface with no protrusion. Countersunk semi-tubular rivets appear in applications where surface clearance matters: conveyor components, sliding mechanisms, and enclosures that must stack or nest.
Button Head
A low, rounded head that provides moderate bearing area with a neat appearance. Button head rivets bridge the gap between oval and flat styles and are frequently specified in furniture hardware and decorative metalwork.
Materials and Finishes
Semi-tubular rivets are manufactured from a range of metals, each suited to different operating environments:
Steel (low-carbon mild steel) — The workhorse material for general industrial use. Offers high shear strength at low cost. Typically zinc-plated or black-oxide coated to resist corrosion. Used in automotive brakes, appliances, and general manufacturing.
Stainless Steel (304 / 316) — Chosen where corrosion resistance is critical: food processing equipment, marine hardware, medical devices, and outdoor installations. 316-grade stainless provides superior resistance to chloride environments.
Aluminum — Lightweight and naturally corrosion-resistant. Common in aerospace sub-assemblies, electronics, and applications where weight savings matter. Aluminum rivets also avoid galvanic corrosion when joining aluminum workpieces.
Brass — Excellent corrosion resistance, electrical conductivity, and an attractive gold finish. Widely used in electrical terminals, decorative hardware, marine fittings, and musical instruments.
Copper — Superior electrical and thermal conductivity, plus natural antimicrobial properties. Specified for electrical connections, heat exchangers, and applications in healthcare or food-contact environments.
Titanium — The highest strength-to-weight ratio and exceptional corrosion resistance. Reserved for aerospace, medical implants, and high-performance applications where cost is secondary to performance.
Common surface treatments include zinc plating, nickel plating, zinc-iron (ZnFe), zinc-nickel (ZnNi), chromate conversion coating, black oxide, and custom powder coating or paint to match product aesthetics.
Industry Applications
Semi-tubular rivets serve virtually every manufacturing sector. Here are the applications where they dominate:
Automotive — Brake linings and pads, clutch facings, seat frames, door hinges, interior trim panels, wiper assemblies. The automotive industry consumes more semi-tubular rivets than any other sector, driven by the need for high-speed automated assembly and consistent joint quality.
Electronics & Electrical — Circuit board standoffs, terminal connections, transformer assemblies, switch gear, and enclosure fastening. Brass and copper semi-tubular rivets provide both mechanical joining and electrical continuity in a single fastener.
HVAC & Appliances — Ductwork seams, blower housings, refrigerator hinges, washing machine drums. The combination of speed, low cost, and reliable joints makes semi-tubular rivets the default fastener for white-goods assembly lines.
Furniture & Hardware — Office chair mechanisms, cabinet hinges, drawer slides, shelving brackets. Semi-tubular rivets create pivot joints that allow controlled movement—a capability that solid rivets and threaded fasteners cannot easily replicate.
Leather Goods & Textiles — Belts, bags, luggage, footwear, and canvas products. Self-piercing semi-tubular rivets can punch through soft materials without pre-drilled holes, simplifying production.
Stationery & Office Products — Three-ring binders, clipboards, file folders. These high-volume consumer products rely on semi-tubular rivets for their combination of speed, cost, and the ability to form pivot joints.
Aerospace (non-structural) — Interior panels, galley equipment, lavatory fittings, and secondary structures where weight savings and moderate shear strength are sufficient.
How to Size Semi-Tubular Rivets: A Step-by-Step Guide
Correct sizing ensures a strong, reliable clinch without damaging the workpiece. Three dimensions matter: diameter, length, and hole depth.
Step 1: Determine Rivet Diameter
The rivet body diameter must match the pre-drilled or pre-punched hole in your workpiece. Standard diameters range from 1/16″ (1.6 mm) to 3/8″ (9.5 mm) for most applications, with larger sizes available up to 5/8″ (16 mm) for heavy-duty work.
As a rule of thumb, rivet diameter should be approximately 1.5 to 2 times the thickness of the thinnest sheet being joined. A diameter that’s too small risks shear failure; too large wastes material and requires unnecessarily high setting force.
Step 2: Calculate Required Length
Rivet length (the “L” dimension) is measured from the underside of the head to the end of the tail. The correct length equals:
Total material thickness + clinch allowance
For semi-tubular rivets, the clinch allowance—the amount of shank that must protrude beyond the workpiece to form a proper clinch—is typically 2.5 mm to 3.5 mm (approximately 0.100″ to 0.140″). This is significantly more than the 1.0–1.5 mm allowance for solid rivets, because the tubular tail needs enough material to roll outward and form a secure flange.
Example: If you’re joining two sheets with a combined thickness of 4.0 mm, you need a rivet length of 4.0 + 3.0 = 7.0 mm.
Step 3: Verify Hole Depth Specification
The cavity depth in the tail must be less than 112% of the mean body diameter—this is the IFI (Industrial Fasteners Institute) standard that defines a rivet as “semi-tubular” rather than “tubular.” A deeper cavity would classify the rivet as fully tubular and change its clinching behavior.
Step 4: Select Clinch Type
Two clinch styles are standard:
- Roll clinch — The tail curls outward in a smooth, even flare. Provides maximum joint strength and is the default for most applications.
- Star (scored) clinch — The tail splits into segments that fold outward like petals. Used with soft materials (leather, plastics, thin fabrics) where a roll clinch might tear through. Washers or burr caps can be added beneath the clinch for additional bearing surface.
Quick Sizing Reference Table
| Rivet Diameter | Recommended Hole Size | Clinch Allowance | Typical Applications |
|---|---|---|---|
| 1/16″ (1.6 mm) | 0.067″–0.070″ | 2.5 mm | Electronics, miniature assemblies |
| 3/32″ (2.4 mm) | 0.099″–0.104″ | 2.5 mm | Stationery, light hardware |
| 1/8″ (3.2 mm) | 0.133″–0.136″ | 3.0 mm | General light-duty |
| 5/32″ (4.0 mm) | 0.164″–0.169″ | 3.0 mm | Appliances, HVAC |
| 3/16″ (4.8 mm) | 0.196″–0.201″ | 3.0 mm | Automotive, furniture |
| 1/4″ (6.4 mm) | 0.261″–0.266″ | 3.5 mm | Brakes, heavy assemblies |
| 5/16″ (7.9 mm) | 0.323″–0.328″ | 3.5 mm | Industrial machinery |
| 3/8″ (9.5 mm) | 0.386″–0.391″ | 3.5 mm | Heavy-duty structural |
Installation Methods
Semi-tubular rivets can be installed using several methods, depending on production volume and precision requirements:
Impact riveting — A ram strikes the rivet tail with controlled force, forming the clinch in a single stroke. Cycle times as fast as 0.3 seconds make this the preferred method for high-volume automated production. Impact riveting machines handle the vast majority of semi-tubular rivet installations in automotive and appliance manufacturing.
Orbital (radial) riveting — A forming tool traces a circular path over the rivet tail, progressively rolling the material outward. This method applies lower instantaneous force, reducing stress on delicate workpieces and producing a smoother clinch. Ideal for electronics, precision instruments, and assemblies with nearby heat-sensitive components.
Spin riveting — Similar to orbital riveting but with the tool rotating on its own axis. Produces a very uniform clinch and is used where cosmetic finish quality matters.
Manual riveting — A hand-operated press or hammer-and-anvil setup for low-volume work, prototyping, and field repairs. Adequate for soft materials and small-diameter rivets.
Self-piercing installation — For materials like leather, some plastics, and light sheet metals, semi-tubular rivets can pierce the workpiece and clinch in a single operation without pre-drilled holes. This eliminates a production step and is common in leather goods and textile manufacturing.
Why Manufacturers Are Switching to Semi-Tubular Rivets
The economics are compelling. A manufacturer running 700,000 assemblies per year who switches from blind (pop) rivets to semi-tubular rivets typically recovers the equipment investment within 12 months through lower per-unit fastener cost and faster cycle times. The total cost of ownership—factoring in rivet price, tooling, energy consumption, and labor—favors semi-tubular rivets in nearly every high-volume application that doesn’t require single-side access.
Beyond cost, semi-tubular rivets offer:
- Consistent quality — Automated installation produces uniform clinches with measurable, inspectable results on every cycle.
- No consumables — Unlike pop rivets, there’s no spent mandrel to collect or dispose of.
- Vibration resistance — The permanent mechanical interlock won’t loosen over time, unlike threaded fasteners in high-vibration environments.
- Design flexibility — Available in virtually any combination of diameter, length, head style, material, and finish to match your exact specification.
How to Source Semi-Tubular Rivets for Your Project
When selecting a supplier for semi-tubular rivets—especially for OEM production volumes—consider these factors:
- Manufacturing capability — Does the supplier cold-head rivets in-house, or are they a distributor? Direct manufacturers offer better pricing, tighter tolerances, and the ability to produce custom specifications.
- Material range — Can they supply the exact alloy and temper you need? A supplier limited to steel and aluminum may not serve your brass or stainless requirements.
- Custom sizing — Standard catalog sizes don’t always match your assembly. Look for suppliers who manufacture to print with reasonable minimum order quantities.
- Quality certifications — ISO 9001 is the baseline. Automotive (IATF 16949) or aerospace (AS9100) certifications matter if your end product requires them.
- Lead time and inventory — For production continuity, you need a supplier who maintains stock on your most-used sizes and can deliver custom orders within predictable lead times.
At yiwan.net, we manufacture and export semi-tubular rivets in steel, stainless steel, aluminum, brass, and copper—with full custom sizing available. Whether you need standard catalog rivets shipped from stock or a custom specification manufactured to your drawing, our engineering team can help you select the right rivet for your application.
Request a free quote → | View our semi-tubular rivet catalog →
Frequently Asked Questions
What is the difference between a semi-tubular rivet and a tubular rivet?
The distinction is the cavity depth. A semi-tubular rivet has a hole depth less than 112% of its mean body diameter. A fully tubular rivet has a deeper cavity (or is hollow through its entire length). Semi-tubular rivets provide higher shear strength because more of the body is solid material.
Can semi-tubular rivets be removed?
Semi-tubular rivets form permanent joints. Removal requires drilling out the rivet head or grinding it off. This is by design—the permanent joint eliminates loosening, tampering, and the need for torque maintenance.
What force is needed to install a semi-tubular rivet?
Approximately 25% of the force required for a comparable solid rivet. The exact force depends on rivet diameter, material hardness, and clinch type. Your riveting equipment manufacturer can provide force specifications for your specific rivet size.
Are semi-tubular rivets suitable for structural applications?
They excel in light-to-medium structural applications: automotive brakes, appliance frames, furniture mechanisms, and HVAC assemblies. For primary structural joints in aerospace or heavy steel construction, solid rivets or high-strength bolts are typically specified instead.
What is the minimum order quantity for custom semi-tubular rivets?
This varies by manufacturer. At yiwan.net, we offer competitive MOQs for custom sizes and can work with you on prototype quantities before committing to full production runs. Contact our team to discuss your requirements.
Looking for a reliable semi-tubular rivet supplier for your next production run? Yiwan manufactures precision semi-tubular rivets in all standard and custom specifications, with factory-direct pricing and global shipping. Get a quote today →