The best combination squares, compared.
Top pick: Tracer combination square set Best value: Faithfull combination square, 150 mm – Best value at £6.99 for a 150 mm square with 4.5 from 1,551 reviews, once you have read the length. Updated 22 October 2026.
A combination square is a steel rule that slides through a metal head and locks. The head has a 90° face and a 45° face, and it usually carries a small vial and a scribe. In the UK you use one for joinery layout, skirting and marking metal. It is not a fixed engineer's try square. You judge a suitable square by whether the head stays square to the rule, whether the lock holds when you push the blade, and whether you need 150 mm in a pouch or 300 mm on the bench. Part of the blade sits inside the head, so the usable span is shorter than the nominal length. Scales may be metric, imperial, or both. A class I mark on a listing is a tolerance on the rule, not proof the head is square. BS 939:2007 leaves adjustable squares out. The vial is a short bubble, not a long spirit level. How to lock, mark and flip-test is on the [how to use a combination square](/hub/measuring-and-marking-tools/combination-square/sub/combination-square-how-to-use) page.
A combination square is a steel rule that slides through a metal head and locks. The head has a 90° face and a 45° face, and it usually carries a small vial and a scribe.
42 products checked · 61 hrs invested · +19,400 readers
Swipe for more
1-2 of 12
Personal buying guide
Question 1 of 2
Where will you mark?
Tracer ACSQKIT-E is a 150 mm and 300 mm set at £34.99, with stainless blades, cast handles, a vial and a scribe. The listing weight is 720 g, the heaviest pair in this set, and the origin is China. amazon.co.uk shows 5.0 from 2 reviews. The stored reviews include one UK review, which says the kit feels sturdy and locks tight, and that is the whole text sample. The page asks whether the spirit level is accurate and does not answer it. The only review does not mention the vial. Dimensions and the material field are missing from the listing details. It is a kit to check yourself if you already want model ACSQKIT-E, and the 5.0 score is not a pattern.
Pros
Cons
Best for: You want Tracer’s two-size kit, model ACSQKIT-E, and you will check it yourself.
Less suitable: You are buying on the 5.0 score. Two reviews are not a pattern.
Specifications
Common questions
What is in the Tracer kit?
The title says 150 mm and 300 mm. The highlight says two stainless squares with metric and imperial scales, 45° and 90°, a spirit level and a scribe. Weight is 720 g. The listing price is £34.99.
Is the spirit level accurate?
That question is on the page and is not answered on the listing. The bullets claim a built-in level. The only review does not mention the vial.
How many review texts are stored?
The listing says 5.0 from 2. The stored reviews include one UK review, which says the kit feels sturdy and locks tight. That is the whole text sample.
WORKPRO W064028 is a 300 mm combination square at £25.91, with a 2 mm stainless rule, a zinc-alloy head, a bubble and a detachable marking pin. The listing weight is 410 g, heavier than the £7.99 300 mm square in this set, and a case is not stated. amazon.co.uk shows 4.7 from 5,203 reviews and rank 10 in Carpentry Squares. Across the first 50 reviews, buyers describe a lock that holds and faces that agree at 45° and 90°. That sample does not show a repeated breakage. One review still calls the price high, another mentions a sharp rule edge, and a third found the slide a bit rough. It is the top pick here for a single 300 mm square with a stated 2 mm rule and a large review count. It is the wrong length if you need a 150 mm pouch square or a metric-only blade.
Pros
Cons
Best for: You want a single 300 mm square with a stated 2 mm rule and a large review count.
Less suitable: You need a 150 mm pouch square, or a metric-only blade. This listing is 300 mm with metric and inch scales.
Specifications
Common questions
How long is the WORKPRO blade?
The title and bullets say 300 mm / 12 in. The bullets also say the stainless rule is 2 mm thick. The listing weight is 410 g.
Does it include a level and a scribe?
The bullets include a spirit level. The highlight field says a detachable marking pin. A case is not stated.
What do the first 50 reviews repeat?
They mostly call it solid, locking, and accurate at 90° and 45°. One review mentions a sharp rule edge and a slightly rough slide. No repeated breakage is in those 50 texts.
PRESCH 10110 is a pair at £34.99, with 150 mm and 300 mm blades, cast-zinc heads, brass locks, stainless rules and metric marks only. The listing weight is 580 g, and the bullets mention a storage box plus a scribing needle. amazon.co.uk shows 4.6 from 5,303 reviews, the largest count in this set, and rank 29 in Carpentry Squares. The first 50 reviews praise the millimetre scales and a firm lock. The same sample repeats sharp edges, a stiff or fragile thumbscrew, a rule that creeps, and heads that were not square on arrival. One reviewer measured the short blade as 152.4 mm, which is 6 in, even though the scales are metric. Choose it when you want both lengths and millimetres only, and you will flip-test both heads. Leave it if you still mark in inches.
Pros
Cons
Best for: You want both lengths and millimetre scales only, and you will flip-test both heads.
Less suitable: You still mark in inches, or you want a single cheap 300 mm. This set is £34.99 and metric only.
Specifications
Common questions
Are the PRESCH scales metric and imperial?
The bullets and the reviews describe millimetre scales on both sides, not inches. One reviewer still measured the short blade as 152.4 mm, which is 6 in.
What is in the set?
The title is 150 mm and 300 mm. Number of items is 2. Included components name a universal angle, a ruler and a scribing tool. The stock is cast zinc with a brass lock.
What faults show up in the first 50 reviews?
Praise is for the metric scales and a firm lock. Repeated complaints are sharp edges, a stiff or fragile thumbscrew, a rule that creeps, and heads that were not square on arrival.
Faithfull FAICS300TCNC is a 150 mm and 300 mm pair at £28.49, in black anodised aluminium, listed at 370 g. The bullets claim a 10-year Prestige guarantee, while the EU spare-part field says 1 year. amazon.co.uk shows 4.6 from 289 reviews. All 28 texts on the listing praise the white-on-black scales and a smooth slide. Several of those texts call the aluminium rule flimsy, one square stiff and the other loose, or the finish scratched. One review limits the set to DIY, and one mentions a case. It suits you if you want both lengths and high-contrast scales, and you will not throw the rules in a heavy bag. It is the wrong pair if you wanted a cast-iron stock or a thick steel rule.
Pros
Cons
Best for: You want both lengths and high-contrast scales, and you will not throw the rules in a heavy bag.
Less suitable: You want a cast-iron or thick steel rule. Reviewers say this blade is aluminium.
Specifications
Common questions
What are the Prestige squares made of?
The bullets say CNC-machined aluminium with a black anodised finish. The material field says aluminium. Reviewers say the rule is aluminium as well, and some call it flexible.
How long is the guarantee on the listing?
The bullets and the warranty field both say 10 years for the Prestige range. The EU spare-part field says 1 year. The set is 150 mm and 300 mm at £28.49.
What do the 28 reviews say?
They praise the white-on-black scales and a smooth slide. Several say the blade is flimsy, one square was stiff and the other loose, or the finish scratched. One review limits it to DIY.
Faithfull FAICS150 is a 150 mm combination square at £6.99, with a cast and machined stock, a stainless rule, a vial and a scribe. The listing weight is 99.8 g, and the model field is 150 mm rather than a 12 in blade. amazon.co.uk shows 4.5 from 1,551 reviews and rank 14 in Carpentry Squares. The first 50 reviews treat the pocket size as useful on small timber, and as the main surprise when buyers expected a longer rule. Two reviews say the vial is hard to see or mostly covered. Other complaints in that sample are a rule that is awkward to refit, one stock that snapped after a drop, and one head that was not 90°. It is the best value here if you have read the 150 mm length and you are marking small sections. It will not reach across sheet goods or a long run of skirting.
Pros
Cons
Best for: You want a 150 mm square for small sections and you have read the length.
Less suitable: You are marking sheet goods or long skirtings. This blade is 150 mm and weighs 99.8 g.
Specifications
Common questions
Is this the 12 in Faithfull square?
No. The title, model FAICS150 and the graduation field say 150 mm (6 in). The listing weight is 99.8 g. Reviewers often say it is smaller than they expected.
Does the 150 mm square have a level and a scribe?
The bullets say a spirit level and a marking scribe in the sliding stock. Two reviews say the vial is hard to see or mostly covered. A case is not in the included components.
What do reviewers praise and reject?
The first 50 reviews praise the pocket size for small timber. Complaints are the size surprise, a hard-to-read vial, a rule that is awkward to refit, one snapped stock after a drop, and one head that was not 90°.
Tracer ACSQ150 is listed at £15.83 as a 150 mm stainless square, 160 g, with a vial and a retractable scribe. The listing shows 4.5 from 107 reviews and rank 8 in Carpentry Squares. Those figures, and the same 13 review texts, also appear on the 300 mm Tracer square. The texts themselves fit a small pocket square, and one review says the green body is easier to see than orange. One of those texts reports a missing gold bolt, and another says it is dearer than a basic 150 mm square. The written sample is only 13 texts, so you cannot read a separate text for all 107 reviews. It is a pouch option if you accept that the review block is shared. The model field is ACSQ150, so it is not a 300 mm blade.
Pros
Cons
Best for: You want a 150 mm Tracer square for a pouch, and you accept that the written reviews are a shared block.
Less suitable: You need a 300 mm blade. This model field is ACSQ150.
Specifications
Common questions
What length is ACSQ150?
The title and bullets say 150 mm / 6 in. The listing weight is 160 g and the listing price is £15.83.
Does it have a level and a scribe?
The bullets say an integrated vial and a retractable scribe for timber and tile. A case is not stated.
Are these reviews only for the 150 mm square?
The stored reviews include 13 UK reviews, 4.5 from 107, and the same texts and rank line as the 300 mm Tracer square. The texts describe a small pocket square. One says a gold bolt was missing.
Tracer ACSQ300 is listed at £24.00 as a 300 mm stainless square, 355 g, with a vial and a scribe pin, and the origin field says China. Dimensions on the listing are 31 x 14 cm, and a case is not stated. The review block on the listing is the same 13 texts, the same 4.5 from 107, and the same rank line as ACSQ150. Several of those texts describe a pocket or 6 in square, so they are not a separate test of this 300 mm head. One shared review says a gold threaded bolt was missing. Treat the length on the title as the specification, and the stars as a shared figure. Buy model ACSQ300 only if you will judge the head yourself. Do not use this star rating as proof the 300 mm square was reviewed on its own.
Pros
Cons
Best for: You want the 300 mm Tracer model number ACSQ300 and you will judge the head yourself.
Less suitable: You are using the star rating as proof this 300 mm square was reviewed on its own. The review texts match the 150 mm square.
Specifications
Common questions
What does the listing say the length is?
The title and bullets say 300 mm / 12 in, model ACSQ300, 355 g, £24.00. Dimensions are 31 x 14 cm.
Why do the reviews describe a 6 in square?
These stored reviews contain the same 13 UK reviews, the same 4.5 from 107, and the same rank line as the 150 mm Tracer square. Several texts describe a pocket or 6 in square. They are not a separate test of this 300 mm head.
Is a scribe included?
The bullets say a scribe pin and a built-in spirit level. One review in the shared block says a gold threaded bolt was missing.
Auyuiiy CZ-10086 is a 300 mm combination square at £7.99, with a stainless rule, a zinc-alloy head, a bubble and a metal scriber. The listing weight is 280 g, and the listing ranks it 2 in Carpentry Squares. amazon.co.uk shows 4.4 from 1,454 reviews. Across the first 50 of those reviews, buyers like the price and the vial. The same sample repeats a fiddly spring-loaded screw, sharp edges, a flimsy feel, a head that was not square, a seized screw, and graduations that wore off. The title says engineers square, but the product is an adjustable head, so it is not a fixed try square. It suits a cheap 300 mm DIY square if you flip-test it before you cut. Reviewers who wanted a lock they do not have to fight compare the feel with a toy.
Pros
Cons
Best for: You want a cheap 300 mm square for DIY and you will flip-test it before you cut.
Less suitable: You want a cast-iron head or a lock you do not have to fight. Reviewers compare this one with a toy.
Specifications
Common questions
Is the Auyuiiy square 300 mm?
The bullets say a 300 mm steel rule and a 12 in scale. The graduation field says 0–12 inches. The listing weight is 280 g and the listing price is £7.99.
Does it have a level and a scribe?
The bullets say a built-in bubble and a metal scriber, and 45° and 90° marking. A case is not stated. The title says engineers square; the product is an adjustable head.
What goes wrong in the reviews?
Across the first 50 of 1,454 reviews, buyers like the price and the vial. Repeated faults are a fiddly spring-loaded screw, sharp edges, a flimsy feel, a head that was not square, a seized screw, and graduations that wore off.
Faithfull FAICS300TP is a 150 mm and 300 mm pair at £19.91, with cast and machined stock, stainless rules, a vial and a scribe. The listing weight is 480 g, heavier than the aluminium Prestige pair in this set. amazon.co.uk shows 4.4 from 236 reviews. The stored reviews include 24 texts, and they like having both sizes. One would not trust the vial, one says a head was not close to 90°, and one says the spring and brass fitting wore out after about a year. A review mentions a screwed scribe. The bullets say a five-year guarantee and the warranty field says one year, so the listing does not give you a single stated term. It suits you if you want Faithfull’s cast-stock squares in both lengths at this price, and you will still flip-test both heads.
Pros
Cons
Best for: You want Faithfull’s cast-stock squares in both lengths at £19.91.
Less suitable: You need a single stated guarantee. The bullet and the warranty field do not match.
Specifications
Common questions
What is in the Faithfull twin pack?
Included components say one 150 mm and one 300 mm combination square. Model FAICS300TP. The listing price is £19.91. Weight is 480 g.
How long is the guarantee?
The bullets say five years. The product warranty field says one year. Both lines are on the listing, so the listing records both.
What do the 24 reviews say?
They like having both sizes. One would not trust the vial. One says a head was not close to 90°. One says the spring and brass fitting wore out after about a year.
flintronic F1EU-6300596 is a 150 mm and 300 mm pair at £12.99, with stainless rules, aluminium-alloy handles, a vial and a marker pin. The listing weight is 302 g, the origin is China, and dimensions are not stated. amazon.co.uk shows 4.4 from 61 reviews and rank 47 in Carpentry Squares. The stored reviews contain 10 short texts against that count of 61, so the sample is thin. Most of those 10 say it does the job. One calls it a bit flimsy, and one says the quality is poor. A case is not in the bullets, though one review mentions two pencils. It is a low-priced twin pack if you will check both heads. It is light if you wanted a heavy cast head.
Pros
Cons
Best for: You want a low-priced twin pack and you will check both heads.
Less suitable: You want a heavy cast head. This set is 302 g with aluminium-alloy handles.
Specifications
Common questions
Does the flintronic set include both lengths?
The title and the colour field say 150 mm and 300 mm. Unit count is 2. The price on the listing is £12.99 and the weight is 302 g.
Is a case included?
A carrying case appears only as a question heading. The bullets do not list a case. One review mentions two pencils.
What do the 10 reviews say?
Most are short and positive, or say it does the job. One says it is a bit flimsy. One says the quality is poor. The listing count is 61, so these 10 texts are a sample.
Stanley STA046151, also written 0-46-151, is a 300 mm combination square at £23.78, with a cast-iron stock on the bullets, machined faces, an etched rule, an embedded scribe and a listed weight of 430 g. amazon.co.uk shows 4.2 from 180 reviews and rank 124 in Carpentry Squares. The Class I line on the bullets is attached to the steel rule, not to the head. The first 50 reviews praise the weight, and some found 90° and 45° true. Others report the stock out of square, including about 1.5 mm to 2 mm along the blade, plus sharp casting edges. Reviews also say the brass nut must be tight or the rule slips, and one says the scribe is very hard to remove. A case is not in the included components, and reviews say the rule reverses. It is the Stanley cast-iron option if you will flip-test it, and a weak buy if you wanted a square you can trust from the title alone.
Pros
Cons
Best for: You want the Stanley cast-iron 300 mm, model STA046151, and you will flip-test it.
Less suitable: You want a square you can trust from the title alone. A large share of the first 50 reviews say this head arrived out of square.
Specifications
Common questions
What does Stanley claim this square is?
Bullets say a cast-iron stock, machined faces, an etched metric and imperial blade, and a Class I accuracy steel rule. Model STA046151, also written 0-46-151. The listing price is £23.78. Weight is 430 g.
Does Class I mean the head is square?
The bullet attaches Class I to the steel rule. The first 50 reviews disagree about the head: some found 90° and 45° true, others report the stock out of square, including about 1.5 mm to 2 mm along the blade.
Can the rule come out?
Reviews say the rule reverses and that the brass nut must be tight or the rule slips. One review says the scribe is very hard to remove. A case is not in the included components.
Makloee CDT01582-CHQ is the cheapest twin pack in this set, at £6.98 for a 150 mm and a 300 mm square with a spirit level and a marking needle. The listing weight is 230 g, the dimensions are 30 x 15 cm, and the bullets describe metric graduations without an imperial scale. amazon.co.uk shows 3.7 from 11 reviews. Three UK review texts are stored. One says the level is not accurate, one would not recommend it, and one says it is flimsy and has no spring. A combination square that will not hold a set length cannot repeat a mark, so the missing spring is the serious line in that sample. It is only a candidate if you want the lowest price and you will not rely on the vial. The three texts do not describe a rigid square.
Pros
Cons
Best for: You want the cheapest twin pack in this set and you will not rely on the vial.
Less suitable: You want a square reviewers describe as rigid. The three texts do not say that.
Specifications
Common questions
What do you get for £6.98?
The title says a 300 mm and a 150 mm combination square with a spirit level and a marking needle. Number of items is 2. Weight is 230 g. Part number CDT01582-CHQ.
Do the reviews support the level?
Three UK reviews are stored, against a listing count of 11 at 3.7. One says the level is not accurate. One would not recommend it. One says it is flimsy and has no spring.
Are the scales imperial as well?
The bullets describe metric graduations. An imperial scale is not stated.
Twelve amazon.co.uk listings, captured on 19 October 2026, were read for this page. Each score takes the star average as a 0–80 band and adds a small amount for a large review count. There was no laboratory check of squareness. The top pick is the highest of those scores. Best value is the £6.99 150 mm square with 1,551 reviews, not the £6.98 twin pack and not the next score down.
Amazon star rating
80%The listing average is placed on a 0–80 band. A 4.7 becomes 75. A 3.7 becomes 59. Stars are not a squareness grade and they are not BS 939.
Review-file size
20%A large count adds up to 10 points. 5,203 reviews add 10. Two reviews add nothing. A shared Tracer review block is not a separate test of the 300 mm head.
Choose the length, then the lock, then the stock and the scales. The vial and the scribe come after that. The table is the twelve listings. None of these squares was checked in a lab, and a star average is not a BS 939 grade.
A combination square is a rule that slides through a metal head and locks. The head gives you 90° and 45°. A small vial and a scribe are usual, and they are secondary. In UK joinery you use it to mark skirting, shelves and metal. A single sliding head is this category. A twin pack is two complete squares, not one head with spare blades. A centre head or a protractor is a different set. A try square does not slide. A speed square is a roofing triangle. Length comes first.
150 mm suits hinges, narrow timber and a pouch. Reviewers of the short Faithfull square often say it is smaller than they expected. It will not reach across sheet goods or a long run of skirting. Part of any blade sits in the head, so the usable span is shorter than the nominal length.
Tighten the nut and try to push the rule before you trust a price. Creep, a seized spring screw, or a head with no spring means the square will not repeat a mark. One Makloee review says there is no spring. Stanley reviews say the brass nut must be tight or the rule slips.
Class I on Stanley's rule is a length tolerance under SI 2016/1153, not proof the head is square. BS 939:2007 excludes adjustable squares. The vial is not a long spirit level. If the flip test diverges, return a new square rather than filing it.
Length is the first decision. 150 mm, also sold as 6 in, suits hinges, narrow timber and a pouch. 300 mm, also sold as 12 in, suits skirting, sheet layout and setting a fence. Part of the blade sits in the head, so you cannot mark the full nominal length from the stock face. The 150 mm Faithfull square weighs 99.8 g, and reviewers often say it is smaller than they pictured. The WORKPRO and Auyuiiy rows are single 300 mm squares.
Stock and rule are what you feel in the hand. Stanley STA046151 claims a cast-iron head and a listed weight of 430 g. WORKPRO W064028 claims a 2 mm stainless rule and a zinc head at 410 g. PRESCH claims cast zinc and a brass lock. The Prestige pair is anodised aluminium, and reviewers say that rule bends. Cheap rules arrive with sharp edges. A heavier listing is not a measured grade. Most of this set is metric and imperial. PRESCH is metric only, which reviewers either want or miss.
Three typical situations, each with a recommendation from this comparison.
You want a 300 mm square for skirting, sheet layout or setting a fence, and you will flip-test it before you cut. The WORKPRO is that single 300 mm row, at £25.91, with a stated 2 mm rule and 4.7 from 5,203 reviews. A case is not stated.
You want 150 mm for hinges, narrow timber and a pouch, and you have read the length. The Faithfull FAICS150 is £6.99 at 99.8 g, with 4.5 from 1,551 reviews. Reviewers often say it is smaller than they pictured. Keep a 300 mm square in the box if you also mark long runs.
You want millimetres on both blades and you will flip-test both heads. The PRESCH pair is 150 mm and 300 mm at £34.99, metric only, with cast zinc and a brass lock on the listing. amazon.co.uk shows 4.6 from 5,303 reviews. Leave it if you still mark in inches.
The top pick is the WORKPRO combination square, 300 mm, at £25.91. amazon.co.uk shows 4.7 from 5,203 reviews. The listing states a 2 mm stainless rule and a zinc-alloy head at 410 g, and the first 50 reviews describe a lock that holds. One review still calls the price high, and a case is not stated. The best value is the Faithfull combination square, 150 mm, at £6.99, with 4.5 from 1,551 reviews. Reviewers often say that blade is smaller than they expected. The £6.98 twin pack is cheaper and has a much thinner review file.
Faithfull combination square, 150 mm
Best value at £6.99 for a 150 mm square with 4.5 from 1,551 reviews, once you have read the length.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Sources taken from the research digest. Listings were captured on 19 October 2026.
This article contains affiliate links. If you buy through these links we may earn a small commission, at no extra cost to you. Prices, stars and review counts come from stored amazon.co.uk listings. We did not measure these squares in a lab.
