Three different mechanisms
These are the clamps for short reach and quick holding, where a bar clamp would be too long or too slow. They are not interchangeable: each applies its force in a different way (see the plate above), and that decides what it is good for. The clamps guide covers the rest of the family.
Spring clamps
A spring clamp is two arms on a pivot, closed by a spring. You squeeze the handles to open it and let go to clamp — there is nothing to adjust, so it goes on and comes off in a second. The spring sets the force, and it is light. Pony’s classic steel spring clamps open 1 to 4 in, and Pony says the pressure stays at the jaw tips through the whole opening; vinyl-covered tips protect the work. Its Adjust-A-Clamp lets you set the force between 1 and 50 lb, and plastic spring clamps have pivoting pads that sit flat on angled faces.
- Good for: holding a template or a fence, gluing small parts and edging, holding work while a screw goes in, and any job where you need many clamps quickly.
- Not for: closing a glue joint that needs real pressure, or anything the spring cannot hold against.
C-clamps
A C-clamp is a rigid C-shaped frame with a screw through one end. The screw drives a swivel pad toward the fixed end of the frame, and because a screw multiplies the force of your hand, a C-clamp squeezes hard at one small point. Pony’s light-duty ductile-iron C-clamps open 1 to 8 in with 1 to 4 in of reach and are rated from 400 to 1,000 lb; Bessey’s 540 series, which Bessey recommends for lighter duty including woodworking, opens up to 14 in and is rated from 1,100 to 2,850 lb. Heavy drop-forged C-clamps are rated in the thousands of pounds and are made for steelwork.
- Good for: pinning work to the bench, clamping a stop or jig, holding a patch or a veneer while glue sets, and pressing where a bar clamp cannot reach.
- Limits: the frame sets the reach — the work must fit inside the C — and the small pad dents wood unless a block goes under it. More force than the job needs is easy to apply.
Hand screws
A hand screw is two long wooden jaws joined by two screws. Turning one screw moves the jaws together; turning the other changes the angle between them. Jorgensen makes its jaws of hard maple and its screws of cold-drawn steel with double-lead threads, and says the jaws spread pressure over broad areas without marring finished surfaces. Its sizes run from the No. 3/0, with 6 in jaws opening 3 in, to the No. 2, with 12 in jaws opening 8 in.
- Good for: tapered, angled and odd-shaped parts; delicate or finished work; holding a small part upright on the bench, or clamped to the bench top as a small vise.
- Using one: set the jaws roughly parallel to the work first, close them with the screw nearer the work, then tighten the far screw so the jaw tips bear down — the jaws should meet the work along their length, not just at the ends.
Compared
| Clamp | Opening | Force | Best for |
|---|---|---|---|
| Steel spring clamp (Pony) | 1–4 in | Light; not stated | Quick holding, small glue-ups, templates |
| Adjustable spring clamp (Pony Adjust-A-Clamp) | Not stated | Set between 1 and 50 lb | Delicate parts where force must be limited |
| Light-duty C-clamp (Pony; Bessey 540) | 1–8 in (Pony); to 14 in (Bessey) | 400–1,000 lb (Pony); 1,100–2,850 lb (Bessey) | Pinning work, jigs, local pressure |
| Hand screw (Jorgensen) | 3–8 in; 6–12 in jaws | Not stated | Tapered, angled and finished work |
| One-handed quick clamp (Jorgensen E-Z Hold hobby) | 4–8 in | 50 lb | Light holding with one hand |
Figures are the makers’ own for the models named.
| Job | Clamp | Why |
|---|---|---|
| Hold a template or fence for a moment | Spring clamp | On and off in a second; no adjustment |
| Glue a thin strip or small part | Several spring clamps | Light, even pressure from many points |
| Fix a jig or stop block to the bench | C-clamp with a pad | Holds hard and does not creep |
| Press a patch or inlay flat | C-clamp over a block | Strong local pressure, spread by the block |
| Hold a tapered or angled part | Hand screw | The jaws set to the angle of the work |
| Hold a finished piece | Hand screw, or padded spring clamps | Wooden or padded jaws do not mark |
Protecting the work
Protecting the work from clamp marks
- A block or scrap goes under every small metal pad on finished or soft wood.
- Spring clamp tips are covered, or pads are fitted.
- Squeeze-out cannot reach steel parts that stain wood: wax paper or tape goes between them.
- C-clamps are tightened only until the part stops moving, or the joint closes.
- Hand-screw jaws meet the work along their length, not at one corner.
- Clamp faces are clean of dried glue before they touch the next job.
For long reach, see bar, pipe, parallel and F-clamps; for choosing a first set, how to choose woodworking clamps.
Sources
Openings, reaches and forces are each maker’s own figures for its own clamps. How to use and protect work with them is established bench practice explained in BenchRoot’s own words.
- 1.
Product Catalog, Spring 2024. Pony Jorgensen.
Used for: Classic steel spring clamps opening 1 to 4 in, with pressure kept at the jaw tips throughout the opening and optional vinyl-protected tips; the Adjust-A-Clamp set between 1 and 50 lb; plastic spring clamps with pivoting pads; light-duty ductile iron C-clamps with full-closing Acme screws, 1 to 8 in opening, 1 to 4 in reach, 400 to 1,000 lb; drop-forged heavy-duty C-clamps from 3,300 to 9,300 lb; Jorgensen hand screws with hard maple jaws, cold-drawn double-lead screws and adjustable jaw angle, from the No. 3/0 (6 in jaws, 3 in opening) to the No. 2 (12 in jaws, 8 in opening); E-Z Hold hobby clamps at 50 lb.
- 2.
C-Clamps. BESSEY Tools North America.
Used for: 540 series ductile iron C-clamps recommended for lighter duty, woodworking among it: 0–2-1/2 to 0–14 in capacity, 1-3/4 to 3-3/4 in throat, 1,100 to 2,850 lb; drop-forged series rated to many thousands of pounds for industrial work.
About this guide
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