Woodworking clamps: types, force and glue-up pressure
Which clamp does which job, how hard the makers say their clamps squeeze, and how much pressure a glue joint needs. Every figure names who published it; where nobody publishes a number, this page says so instead of guessing.
Types of clamps and what each is for
Each kind below is described the way two or more published guides describe it, in our own words, with the guides named under it.
Parallel clamps (cabinet clamps). A long steel bar with wide, flat jaws that stay parallel under pressure, so a panel or a cabinet case stays aligned while the glue sets. The strongest of the bar clamps.
F-style bar clamps. A fixed jaw on a bar and a sliding jaw tightened with a screw: the general-purpose clamp for glue-ups, assembly and holding work.
Pipe clamps. Clamp heads that fit onto a length of pipe you buy separately, so the reach is whatever pipe you use. An economical way to clamp tabletops and wide panels.
Bar clamps (steel and aluminum). Long clamps that slide along a flat or I-beam bar for wide assemblies and panel glue-ups. Aluminum bars are lighter than steel but can be less rigid.
One-handed (quick-release, trigger) clamps. Squeeze a trigger to close the jaws with one hand while the other holds the work. Moderate pressure; many reverse into spreaders.
C-clamps. A rigid C-shaped frame and a screw that put strong pressure on a small spot. Their throat is shallow; use pads or blocks so the jaws do not dent the wood.
Spring clamps. Pinch clamps you open with one hand, like a large clothespin. Light pressure: for holding stop blocks, templates and small parts, not for a glue-up that needs force.
Handscrews. Two wooden jaws drawn together by two screws. The wood is gentle on the work, and the jaws can be set at an angle or fitted to odd shapes.
Band and strap clamps. A strap that wraps around the whole assembly and is ratcheted tight, spreading pressure evenly around frames, boxes, chairs and other shapes.
Corner (right-angle) clamps. Hold two parts at 90 degrees while you glue or fasten them: picture frames, boxes and cabinet corners.
Miter clamps. Hold a mitered corner closed while leaving the joint reachable, for picture frames, moldings and trim.
Face clamps. A plier-style clamp that locks, used to hold parts flush during assembly, such as face frames and pocket-hole joints.
Edge clamps. Press onto the edge of a panel, such as when gluing on edging or attaching a face frame; some are add-ons for a bar clamp.
Rubber bands and surgical tubing. Stretchy bands or tubing wrapped around an assembly, for curved and odd shapes no clamp fits.
Sources
- SlashGear, Woodworking clamps: a complete guide to each type (9 June 2025), read 2026-11-08
- This Old House, All about clamps (updated 25 September 2024), read 2026-11-08
- Woodcraft, Woodworking clamps quick start guide (updated 4 May 2026), read 2026-11-08
- Woodsmith, The essential clamps every woodworker needs (18 June 2020); 5 tips for gluing up a panel (13 June 2019), read 2026-11-08
Single guides list more specialised clamps without a second guide to compare: cam clamps, toggle clamps, bench and dog clamps, T-track clamps, pinch dogs, four-way pressure clamps, box clamps and frame clamps (Woodcraft); sash clamps and clutch clamps (SlashGear); clamping cauls (This Old House).
How hard a clamp squeezes: the makers’ ratings
Clamp makers rate their clamps by the most force the screw can put on the jaws. Each figure here is that maker’s own, for that clamp. Bessey prints newtons; pounds-force (lbf) are worked out from it (1 lbf = 4.448 N).
| Clamp | Maker prints | lbf | Throat |
|---|---|---|---|
| Bessey K Body REVO (KRE, KREV) | up to 8,000 N | 1,798 | not printed |
| Pony Jorgensen Cabinet Master Medium-Duty | 1,500 lbs | 1,500 | not printed |
| Pony Jorgensen Cabinet Master Heavy-Duty | up to 2,200 lbs of force | 2,200 | not printed |
| JET Parallel clamp (70411 kit) | 1,000 lbs clamp pressure, 4-1/8 in throat | 1,000 | 4 1/8 in |
| Irwin Quick-Grip XP600 one-handed bar clamp | up to 600 lbs of hold force | 600 | not printed |
One source: each clamp’s maker, the maker of that product
A parallel clamp is rated at about 1,798 lbf, the median of 3 sources (they span 1,000 lbf–2,200 lbf): Bessey, Jorgensen and JET. A one-handed clamp is far lighter: Irwin rates its Quick-Grip XP600 at up to 600 lbf.
Median of 3 sources
A rating is the most the clamp is built for, not what you put on a joint: you tighten by feel, and we found no maker that publishes how much force a hand-tight clamp gives.
How much pressure a glue joint needs
Wood glue wants about 100 psi on the glue line for light, soft woods and up to 250 psi for the densest, from two sources, USDA Forest Products Laboratory and Franklin International (Titebond) (they span 100 psi–250 psi). The USDA’s Wood Handbook explains why: low-density wood presses into full contact easily, while dense wood resists, so it needs more. Too much pressure squeezes or drives the glue out of the joint and starves it.
Only two sources publish this: USDA Forest Products Laboratory and Franklin International (Titebond)
- USDA Forest Products Laboratory: “near 0.7 MPa (100 lb in⁻²)” for low-density wood, “up to 1.7 MPa (250 lb in⁻²)” for the highest-density woods
- Franklin International (Titebond): 100–150 psi softwoods, 125–175 psi medium woods, 175–250 psi hardwoods
| Wood | Pressure |
|---|---|
| Softwoods | 100–150 psi |
| Medium woods | 125–175 psi |
| Hardwoods | 175–250 psi |
One source: Franklin International (Titebond), the maker of that product
Pressure is force spread over the glue area, so a long joint needs much more total force than a short one. Clamp times for each glue are on the wood glue dry time chart, and the glues themselves on wood glue.
Clamps by force: the least that reach the glue maker’s pressure
The glue area times Titebond’s pressure for your wood is the total force the joint needs; one clamp’s rated force, from its maker, divides it. The answer is the fewest clamps of that model that could reach the pressure even at their full rating, not how many to own.
Along the glue line.
For an edge joint, the board’s thickness.
To reach the glue maker’s pressure, at least
3–4 clamps
Minimum total force 4,725–6,750 lbf over 27 in² of glue
One source: Franklin International (Titebond), the maker of that product
One source: Bessey, the maker of that product
Why: At least 3–4 of these clamps to reach the glue maker's pressure: the least, by force, not how many to own.
Spacing: Put clamps both under and over a panel, alternating, so the bars’ pull does not bow the panel toward one face.
Traditional rule, stated by Woodsmith and Laguna Tools
This is the least by force, not how many clamps to own: a rating is the most a clamp is built for, and no two sources give a clamp spacing, so spacing may call for more.
Why these numbers?
The situation
Titebond gives 175–250 psi for hardwoods as the clamping pressure for its wood glues.
One source: Franklin International (Titebond), the maker of that product , sources [1]
What that means
Glue area: 36 in × 0.75 in = 27 in². Force: 27 in² × 175–250 psi = 4,725–6,750 lbf.
Arithmetic: exact by definition
So
Bessey rates the K Body REVO (KRE, KREV) at up to 8,000 N (1,798 lbf): the most it is built for, not what a hand-tight clamp gives.
One source: Bessey, the maker of that product , sources [2]
The number
4,725 ÷ 1,798 = 2.63, so at least 3; 6,750 ÷ 1,798 = 3.75, so at least 4.
Arithmetic: exact by definition
Sources
Clamping a panel glue-up
Put clamps both under and over a panel, alternating, so the bars’ pull does not bow the panel toward one face.
Traditional rule, stated by Woodsmith and Laguna Tools
What no two sources agree on yet
- How far apart to space clamps. Only one guide we read gives a distance (Woodsmith suggests about 6 in as a starting point), so no spacing is given here.
- The “45-degree pressure cone”. Only one publisher we read (Laguna Tools) states it, so it is not given as a rule.
- How many clamps to own, or to use by a rule. No guide we read publishes a number. The calculator above gives only the least by force, from the glue maker’s pressure and the clamp maker’s rating.
All sources
- USDA Forest Products Laboratory, Wood Handbook (FPL-GTR-282, 2021), ch. 10 “Wood Adhesives: Bond Formation and Performance”, Assembly and Pressing, read 2026-11-08
- Franklin International (Titebond), Titebond Original Wood Glue product data: required clamping pressure, read 2026-11-08
- Bessey, K Body REVO KRE/KREV product sheet (03/2025), read 2026-11-08
- Pony Jorgensen, Cabinet Master parallel clamps, read 2026-11-08
- JET, Parallel Clamp Framing Kit 70411 sell sheet (dealer copy), read 2026-11-08
- Irwin, Quick-Grip XP600 one-handed bar clamp press release (21 January 2009), read 2026-11-08
- SlashGear, Woodworking clamps: a complete guide to each type (9 June 2025), read 2026-11-08
- Woodcraft, Woodworking clamps quick start guide (updated 4 May 2026), read 2026-11-08
- This Old House, All about clamps (updated 25 September 2024), read 2026-11-08
- Woodsmith, The essential clamps every woodworker needs (18 June 2020); 5 tips for gluing up a panel (13 June 2019), read 2026-11-08
- Laguna Tools, Five tips for better panel glue-ups (8 March 2021), read 2026-11-08