Stainless Steel Worm Gear Clamps
304 and 316L T-bolt clamps in standard, spring-loaded, and floating bridge configurations. Band widths from 12.7 mm to 25.4 mm. Full material traceability with EN 10204 3.1 as standard.
/ / Quick Specs
What Are Stainless Steel Worm Gear Clamps
A worm gear clamp tightens a stainless band around a hose with a captive screw. The screw thread engages slots stamped into the band. Turning the screw shortens the band. The hose compresses against the fitting shank underneath.
The stamped slots are also the clamp’s weak point. They tear soft hose and they strip under over-torque. We build non-perforated and lined bands for exactly that reason, and we state the screw grade on every order. A clamp is only as stainless as its worst part.
/ / The Procurement Engineer's Problem Profab Solves
A clamp catalog can say “stainless” and mean three different builds. A 304 band with a zinc-plated screw rusts first at the screw. A 316 band with a 410 screw survives longer, but the screw still stains in salt spray. Only the all-316 build holds up in seawater. Band, housing and screw all carry the same grade. The price tracks the mix. The problem for procurement is verifying which mix the batch actually contains.
Profab works from defined material combinations and writes the full build on the packing list. If the screw is 410, the list says 410. You get the same declared grades on the first order and the twentieth, with the rust window of each mix stated before you buy.
Types of Worm Gear Clamps
Three constructions cover the market. Selection depends on hose hardness and how much torque the joint really needs.
/ / 01 — Standard
Standard Worm Gear Clamp
SAE Type F build with a 12.7 mm (1/2 in) perforated band and a 7 mm or 5/16 in hex screw. Sizes run SAE 8 through 104. The everyday clamp for coolant, fuel and utility hose. Keep torque in the 25 to 45 in·lb band. A ratchet can strip the slots in one long pull.
// 02 — Heavy-Duty Hi-Torque
Heavy-Duty Hi-Torque Clamp
Wider 14.2 mm (9/16 in) band with a two-piece riveted housing. Accepts up to 90 in·lb on the larger sizes without the housing spreading. Specified for marine hose, industrial suction lines and any joint that has to survive vibration plus a rough service crew.
// 03 — Non-Perforated Lined Band
Non-Perforated Lined Clamp
The band carries no slots where it touches the hose. Rolled edges and a liner cover the drive section. Built for silicone and soft rubber hose that squeezes up through the slots of a standard band. Use with lower torque and re-check the joint after the first heat cycle.
Material Specification
Stainless Steel Grade Guide
The grade on the box usually describes the band. The screw and the housing are separate decisions. Read the full build, not the band.
304 Stainless
Band, housing and screw all 304. The right build for engine bays, fresh water and indoor plants. Do not run it within sight of the coast or under chlorinated washdown. It pits within one to two seasons, first at the housing seam and the screw thread.
Coolant · Fresh Water · Indoor
316 Band + 410 Screw
The standard marine economy mix. The 316 band shrugs off salt spray. The 410 screw does not. It rusts first and stains the installation while the band still looks new. We build it when asked, with that rust window stated plainly. If the screw must stay clean, move up to the all-316 build.
Coastal · Budget Marine
All-316 (W5 Class)
Band, housing and screw all 316. This is the class that carries marine type approvals such as Lloyd’s Register. Specify it for seawater, chlorinated pool plant and offshore service. One warning: all-stainless threads gall when driven fast. Tighten slowly. The thread micro-welds at speed and locks itself solid.
Marine · Offshore · Chloride
Worm Gear Clamp Specifications
| SAE Size | Clamp Range (in) | Range (mm) | Band Width |
|---|---|---|---|
| 8 | 7/16 – 1 | 11 – 25 | 12.7 mm (1/2") |
| 16 | 13/16 – 1-1/2 | 21 – 38 | 12.7 mm (1/2") |
| 24 | 1 – 2 | 25 – 51 | 12.7 mm (1/2") |
| 40 | 2 – 3 | 51 – 76 | 12.7 mm (1/2") |
| 60 | 3-1/4 – 4-1/4 | 83 – 108 | 12.7 mm (1/2") |
| 104 | 4-1/8 – 7 | 105 – 178 | 14.2 mm (9/16") |
| 152 | 7-1/8 – 10 | 181 – 254 | 14.2 mm (9/16") |
| 188 | 9-3/8 – 12-1/4 | 238 – 311 | 14.2 mm (9/16") |
How to Measure Worm Gear Clamps
- Install the hose first, then measure. The fitting shank stretches the hose OD. That installed OD is the number the clamp must cover, not the hose OD when it sits loose on the bench.
- Pick a size where the installed OD lands in the middle third of the range. At max ID the band overlap runs short. At min ID the tail runs long and catches cables and clothing.
- Band width does the protecting. Soft hose squeezes into the slots of a narrow band. Move up to the 14.2 mm non-perforated band instead of tightening a narrow one harder.
Why Profab Worm Gear Clamps
01
EVERY BATCH HOLDS ITS DECLARED BUILD
Band, housing and screw grades are verified per lot, and the full material mix is written on the packing list. If the screw is 410, the list says 410. You know what the batch contains before it lands on your dock.
02
SLOTS CUT CLEAN, EDGES ROLLED
Slot burrs are the second most common cause of hose damage after over-torque. We deburr the slots and roll the band edges so the band does not chew the hose. Lined bands cover the drive section where it sits against soft rubber.
03
HONEST TORQUE CEILINGS PER SIZE
We publish the install torque for every SAE size, 25 to 45 in·lb for standard bands, up to 90 in·lb for the heavy-duty build. We state the ceiling because a stripped band fails quietly. The joint looks tight until the pressure test says otherwise.
How Worm Gear Clamps Work
Placement
The band wraps the hose over the fitting shank. The housing sits on the band with the screw captive inside.
Engagement
The screw thread bites the slots stamped into the band tail.
Compression
Turning the screw draws the band shorter. The housing holds the screw in place while the tail walks through it.
Sealing
The band compresses the hose onto the shank. Pressure runs highest near the housing. Wide and lined bands spread that pressure around the joint.
Industries We Serve
Marine Raw-Water and Wet Exhaust
All-316 W5 builds on seawater intake and wet exhaust hose. The screw, housing and band all survive salt spray.
Engine Coolant Lines
Standard 304 clamps on coolant hose for stationary engines, generator sets and compressor packages.
Fuel Transfer Lines
304 clamps with rolled edges on diesel and fuel oil transfer hose.
Food and Beverage Process Lines
All-316 non-perforated clamps on transfer hose that sees CIP washdown chemicals.
Pharmaceutical Utility Lines
316 non-perforated builds on purified water and utility transfer hose.
Irrigation and Water Transfer
304 clamps for fresh water. Upgrade to 316 for bore water with dissolved salts.
Pool and Spa Plant Rooms
All-316 builds for chlorinated air around dosing lines and pump connections.
Low Pressure Air and Utility Lines
Standard 304 clamps on workshop air drops. Keep the pressure low. This is not a hydraulic fitting.
Frequently Asked Questions
Can I clamp silicone hose with a worm gear clamp?
Only with a non-perforated or lined band. Silicone squeezes up through the slots of a standard band, and the sharp slot edges shear the cover. Use the lined band with rolled edges and run lower torque. Check the joint again after the first heat cycle.
What torque should I use?
25 to 45 in·lb covers most standard bands. The heavy-duty build accepts more, up to 90 in·lb on larger sizes. Drive with a screwdriver or a torque limiter. A ratchet can strip the slots in one pull, and a stripped band fails quietly.
My clamp is marked 316 but the screw is rusty. What happened?
The band is 316. The screw is probably 410. This is the standard marine economy build. The band survives salt spray. The screw rusts first and stains the joint while the band still looks new. Specify an all-316 build where the band, housing and screw all carry the same grade.
You May Also Need
Stainless Steel Quick Release Clamps
Get in touch with
Ready to Source Stainless Parts?
If you already have the drawings, please send email to [email protected] directly for an instant quote.
Profab
Request a Quote