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Try square vs combination square: which should you buy?

Updated: October 2026

You need to mark a shelf at 90°, but the next job may involve setting a repeated 25 mm offset or checking the depth of a housing. The choice in a try square vs combination square comes down to the mechanism: a try square has a fixed stock and blade, while a combination square has a head that slides and locks along a rule. The five products in the [try square comparison](/hub/measuring-and-marking-tools/try-square) are fixed squares, despite overlapping words in some titles. Choose the fixed tool for straightforward 90° work and fewer moving parts. Choose a combination square when adjustable depth or offset is part of the job.

You need to mark a shelf at 90°, but the next job may involve setting a repeated 25 mm offset or checking the depth of a housing.

Our top picks

WORKPRO WORKPRO 200 mm try square

Best overall

WORKPRO WORKPRO 200 mm try square
9.2/10about £11.99
View offer
S & S PRODUCTS S & S 150 mm try square

Preis-Tipp

S & S PRODUCTS S & S 150 mm try square
8.2/10about £4.49
View offer
Prexiso PREXISO 250 mm try square

Alternative

Prexiso PREXISO 250 mm try square
8.7/10about £16.99
View offer
On this page
  1. 1.Two different mechanisms
  2. 2.What the five compared listings actually are
  3. 3.Buy the adjustable tool when the job demands it
  4. 4.Check either tool before trusting it

Two different mechanisms

A try square forms a fixed L. The stock registers against a straight edge and the blade crosses the face at 90°, with no dimension to lock. That suits repeated cross-lines and carrying a shoulder around prepared faces. A combination square puts the head on a sliding rule. You move the head and lock it, and the projecting rule can gauge depth or transfer a repeatable distance. Many heads also provide a 45° face. Chips under the head, a loose lock or wear on the rule can change the result. A fixed square avoids that lock, but a riveted or punched joint can still loosen. Marking ten boards 30 mm from one edge shows the split. A fixed try square still needs you to locate 30 mm each time. A combination square can lock the head at 30 mm, provided the lock stays secure.

What the five compared listings actually are

S & S, Gunpla, WORKPRO, PREXISO and Presch are fixed squares. Their blades do not slide through a lockable head. Stated lengths from 150 mm to 300 mm change reach, not the mechanism. None is described as a depth gauge. Gunpla's title includes Combination Measuring Square. The bullets describe one aluminium 300 mm or 12 inch square with a vial, not a rule sliding through a head. A screw that trues the blade is not a combination-square head. Buy the mechanism the listing describes, not the search phrase. PREXISO and Presch state a 45° feature. That is another marking angle, not an adjustable depth. WORKPRO is the plainest: a 200 mm fixed blade with metric and imperial marks on both sides. The try square buying guide then helps you choose length, scale and joint.
WORKPRO WORKPRO 200 mm try square

Testsieger

WORKPRO WORKPRO 200 mm try square
9.2/10about £11.99
View offer

Buy the adjustable tool when the job demands it

Choose a combination square to gauge a mortise, set a fence from an edge, or carry one offset across several pieces. The head locks so a chosen length of rule projects below it. A fixed try square cannot do that. Its stock stays at the end of the blade. If you only draw 90° cross-lines, the extra adjustment brings little benefit. A speed square is a third tool: a triangle with a pivot and pitch scale for framing. None of these five listings shows that mechanism, even where Gunpla's wording mentions rafters. Buy the fixed square for quick 90° marks. Buy the combination square when a locked depth removes a separate measuring step.

Check either tool before trusting it

Place the stock or head against a verified straight edge, draw a fine line, flip the tool and draw again. Parallel lines support the 90° setting. Lines that open reveal an error. The method is in how to check a try square. On a fixed square, inspect the joint. S & S reviews mention looseness and glue, and one Gunpla owner reports a failed rivet. On a combination square, confirm the lock holds the rule without shifting it. None of these five states BS 939. For marking with the fixed type, see how to use a try square.

Common questions

When is a fixed try square enough?
It is enough when you mainly mark and check 90° on timber, carry lines around prepared faces and do not need a locked depth. Its fixed form is quick to place and has no sliding head to reset. Choose a blade long enough to cross your usual workpiece.
What can a combination square do that a try square cannot?
Its head slides and locks along the rule, so you can gauge depth and transfer a repeatable offset from an edge. A fixed try square can measure from its stock, but it cannot lock a new head position. Combination heads commonly add a 45° face as well.
Does a 45° face make a try square a combination square?
No. PREXISO and Presch include 45° features while retaining a fixed blade and stock. A combination square is defined here by its sliding, lockable head. The extra angle helps mark a mitre. It does not provide adjustable depth or offset.
Is the Gunpla a combination square?
Its title uses the word combination, but the bullets describe a fixed aluminium square with a vial and a 300 mm or 12 inch scale. No sliding rule or lockable head is described. A screw mentioned in one review appears to true the fixed joint, not set depth.
Can any of these five gauge mortise depth?
Not as a locked depth gauge. Their stocks remain fixed at the end of the blade. You can read a scale manually, but the tool will not preserve an adjustable projection the way a combination-square head does. Use the appropriate adjustable tool for repeated depth checks.
Should you flip-test a combination square?
Yes. Test it at 90° after cleaning and locking the head, then compare lines after reversal. Also check that the rule does not shift as the lock is tightened. A sliding mechanism provides versatility. It does not remove the need to verify the tool.

Related pages

Tape measure

Try square

Best try square: five UK listings matched to a job

Try square buying guide: choose the right size and scale

How to check a try square using a simple flip test

How to use a try square: mark from one reference edge

Sources

Public UK sources for this comparison. Prices, stars and review counts are the amazon.co.uk figures in the listing files, not a live reload.

  1. BSI, BS 3322:1981 — carpenters' squares and bevels (retrieved 16 October 2026)
  2. BSI, BS 939:2007 — engineers' squares (retrieved 16 October 2026)
  3. Wonkee Donkee Tools — engineer's square accuracy (retrieved 16 October 2026)
  4. Wonkee Donkee Tools — how to use a try and mitre square (retrieved 16 October 2026)
  5. Wood Workers Workshop — flip test (retrieved 16 October 2026)
  6. Axminster — measuring and marking (retrieved 16 October 2026)
  7. Axminster — types of woodworking square (retrieved 16 October 2026)
  8. Consumer Rights Act 2015, section 22 (retrieved 16 October 2026)
  9. Faithfull — carpenters' try squares (retrieved 16 October 2026)