What Length Straight Edge Do I Need?

Last updated 11 November 2026

Choose the shortest straight edge that covers your longest regular line in one pass. Every time you move a straight edge part-way through a line, you add another alignment point, and another chance of a step or change of angle. But longer isn’t automatically better. A tool that’s too long costs more, is harder to handle and can be awkward to store. Match the length to the work, the space you have and the accuracy you need.

Quick guide: length by job

Start with your longest regular line

Think about the longest mark, score or cut you make regularly, not the one-off job you do once a year. Choose a tool at least that long. If you’re torn between two sizes, choose the longer one: a long straight edge handles short lines perfectly well, but a short one can’t finish a long line without being moved.

A little overhang helps too. If your straight edge is slightly longer than the line, you can start and finish the mark with the full edge in contact, rather than working right to its tip.

Common material sizes and the lengths that cover them

• A2 and A1 sheets: an A2 cutting mat is typically around 600 × 450 mm; A1 paper is 841 × 594 mm. A 600 mm or 800 mm guide covers most A2 work; cut the long side of A1 with a 1000 mm.
• Wallpaper: standard UK and European rolls are 530 mm wide. A 600 mm straight edge cuts across a roll in one pass.
• 2000 × 1000 mm sheet: a 1000 mm edge spans the width; a 2000 mm edge covers the length.
• 8 × 4 ft board (2440 × 1220 mm) and 2500 × 1250 mm sheet: a 48″ edge matches the 4 ft width exactly; a 1250 mm or 54″ edge gives you a little to spare.
• 3000 × 1500 mm sheet: a 1500 mm edge spans the width; a 3000 mm edge covers the length.
• Vinyl flooring: rolls commonly come 2 m, 3 m and 4 m wide. A 2000 mm or 3000 mm straight edge cuts across 2 m and 3 m rolls in one pass.

Length isn’t the only thing to compare

A long straight edge is only useful if it stays straight and steady in use. Before you buy, compare:

• Stiffness and section. A long, thin or shallow section can flex or sag. Depth and thickness keep a long edge true.
• Weight. Weight helps hold the work still, but makes very long tools harder to lift and position.
• Hand protection. If you’re guiding a knife by hand, a safety profile keeps your fingers clear of the blade along the whole cut.
• Transport and storage. Make sure you have wall space to hang a long tool, and a safe way to carry it.

Generic long rules and feather edges

Long aluminium rules, feather edges and builders’ straight edges are often economical, and they’re fine for construction, flooring, screeding and other low-consequence layout. Many, though, don’t state any straightness tolerance. If the line matters, check what the supplier actually publishes, and check how much the section flexes over its length.

Maun steel straight edges: 12 to 72 inches and 500 to 1750 mm

The Maun steel range covers 15 lengths, from 12″ bench tools to the 72″ (1829 mm): the longest in the range. Every size has the same robust 3.25 mm carbon-steel body, which makes it reassuringly heavy, and a bevelled working edge accurate to 0.001 inch per foot (0.084 mm per metre). The bevel gives you a clear line of sight on the mark or cut.

Choose steel when weight and a hard-wearing edge help: scribing metal, marking gaskets, cutting leather and practical straightness checks, from small components right up to large sheets.

Maun aluminium safety straight edges: 300 to 3000 mm

The Maun aluminium safety range covers ten lengths, from 300 mm to 3000 mm. Every size has a recessed finger-protection profile, non-slip foam-rubber backing and a bevelled working edge accurate to 0.001 inch per foot (0.084 mm per metre).

Choose aluminium when you’re cutting or scoring by hand and want protected fingers, grip on smooth materials and low weight. That low weight is what makes the 2000 mm and 3000 mm lengths practical for one person to handle.

DIN 874 straight edges in long lengths

Specialist suppliers offer DIN 874 inspection straight edges well beyond two metres. These are the right choice when a long reference must meet a defined grade for machine or surface inspection. Expect large DIN 874 tools to be heavy and expensive, with higher costs for shipping, cases and calibration.

Price per use: when a longer tool pays for itself

A correctly sized straight edge often costs less than the material it saves. If moving a short guide part-way through a cut can spoil a sheet of laminate, a hide or a sheet of stainless, the longer tool quickly earns its keep. But if your long lines are rare and low-consequence, a shorter, less expensive straight edge, or a generic long rule for occasional rough layout, may be all you need.

Selection examples

• Small engineering components and gaskets: 12″ or 500 mm steel.
• Model parts, decals and card: 300 mm or 500 mm aluminium safety.
• Belts, straps and bag panels: 24″ to 36″ steel, or 600 to 1000 mm aluminium safety if you want finger protection.
• Metre-wide sheet and panels: 1000 mm steel or aluminium safety.
• Across 8 × 4 ft sheets: 48″ or 54″ steel, or 1250 mm aluminium safety.
• Full hides: 60″ to 72″ or 1500 to 1750 mm steel; 1850 to 2000 mm aluminium safety.
• Sign media and large graphics: 1000 to 3000 mm aluminium safety.
• Vinyl flooring: 2000 mm or 3000 mm aluminium safety.
• Machine beds: 1500 mm, 1750 mm or 72″ steel for practical checks; DIN 874 for formal inspection.

Storage check before you buy a long length

• Do you have wall space to hang the tool flat or vertically from its hanging hole?
• Can you protect the working edge from knocks when it’s stored or carried?
• Can you lift and position it safely: on your own, if you need to?
• Will it fit in your van, rack or workshop?

Which length should you buy?

Buy the shortest straight edge that covers your longest regular line in one pass and meets the accuracy and safety level you need. If you’re between sizes, go longer. If you mostly guide a knife by hand, choose the aluminium safety range. If you need weight, a hard-wearing bevelled edge and practical straightness checks, choose steel.

Compare Maun steel straight edges or compare Maun aluminium safety straight edges.

Frequently asked questions

What length straight edge is best for general workshop use?

For most bench work, 600 mm or 24 inches is a good all-round length. It covers the majority of everyday marking and cutting, yet it’s easy to handle and store. If you regularly work with metre-wide sheet or long hides, add a 1000 mm or longer tool.

Should a straight edge be longer than the cut?

Yes, where you can. A straight edge slightly longer than the line lets you start and finish the cut with the full edge in contact, and avoids moving the tool part-way through.

What straight edge do I need for an 8 × 4 sheet?

To work across the 4 ft (1220 mm) width, choose a 48″ steel straight edge, or a 54″ steel or 1250 mm aluminium safety straight edge for a little to spare. To work along the 8 ft length in one pass, you need a guide of at least 2440 mm; the Maun 3000 mm aluminium safety straight edge covers it.

What’s the longest Maun straight edge?

The 3000 mm aluminium safety straight edge. The longest Maun steel straight edges are the 72″ (1829 mm) and the 1750 mm.

Does a longer straight edge lose accuracy?

The Maun tolerance is stated per foot (or per metre), so the permitted deviation grows in proportion to length. A Maun 1000 mm edge stays within 0.084 mm over its full length; a 2000 mm stays within 0.168 mm. That’s still far better than moving a shorter tool and joining two lines.

Is a heavy straight edge better?

For scribing, marking and cutting thick material, weight is an advantage: it holds the work still. For long hand-guided cuts, low weight and a non-slip backing are easier to manage. Choose by the job.