Combination Sets

About Combination Sets

Combination sets are essential precision measuring and marking tools that bring together multiple instruments in one convenient package. These professional-grade sets typically include a centre head, square head, and protractor head that attach to a graduated steel rule, allowing tradespeople and engineers to perform a wide range of measuring, marking, and layout tasks with a single versatile tool kit. Whether you're working in a machine shop, fabrication workshop, or on-site installation, a quality combination set provides the accuracy and reliability needed for professional engineering work.

Modern combination sets are available in both metric and imperial configurations, with rule lengths typically ranging from 150mm to 300mm (6 to 12 inches). The better quality sets feature hardened and ground steel components with precisely engraved graduations that won't wear away with regular use. Many professional engineers consider a combination set one of the most versatile tools in their kit, as it can replace several individual instruments whilst maintaining exceptional accuracy – typically within 0.001 inches or better on precision models.

Tooled-Up.com stocks combination sets from trusted British and international manufacturers including Moore and Wright, Sealey, Faithfull, and Draper. Whether you need a comprehensive precision set for toolmaking or a practical 4-piece set for general workshop use, you'll find options suitable for both professional tradespeople and serious DIY enthusiasts who demand engineering-grade accuracy in their measuring equipment.

Jargon Buster

• Centre Head: An attachment that locates the centre point of cylindrical work pieces or circular sections. Essential for marking shaft centres and finding the axis of round stock materials.
• Square Head: A 90-degree attachment used for checking and marking right angles, measuring depths, and verifying perpendicularity. Often includes a spirit level for additional functionality.
• Protractor Head: An adjustable component that allows angle measurement and marking from 0 to 180 degrees. Features a graduated scale for setting specific angles with precision.
• Graduated Rule: A hardened steel measuring scale with precision etched or engraved graduations. Available in metric, imperial, or dual-scale configurations, typically with four-sided graduations for versatility.
• Scriber Point: A hardened steel marking pin that can be fitted to certain heads for scoring permanent reference lines on metal work pieces.
• Ground and Hardened: Manufacturing processes that ensure measuring surfaces are perfectly flat, parallel, and resistant to wear, maintaining accuracy throughout the tool's working life.

Who Uses Combination Sets?

Combination sets are invaluable tools across numerous trades and applications:

• Engineering Professionals: Toolmakers, precision engineers, and machinists who require accurate measurement and layout work on the mill or lathe
• Metal Fabricators: Workshop technicians marking cutting lines, checking angles, and setting out complex fabrications in steel, aluminium, and other metals
• Mechanical Fitters: Tradespeople installing machinery, checking alignment, and verifying squareness during assembly and maintenance work
• Joiners and Cabinet Makers: Woodworkers who need to check angles, measure depths, and mark precise centre points for drilling operations
• Quality Inspectors: QA professionals verifying dimensions and angles on manufactured components against engineering drawings
• Apprentices and Students: Those learning engineering, metalwork, or precision woodworking trades who need reliable measuring equipment for training
• DIY Enthusiasts: Serious home workshop users tackling engineering projects, machinery restoration, or precision woodworking
• Maintenance Engineers: Site technicians who need portable precision measuring tools for equipment servicing and repair work

How to Choose the Right Combination Sets

Metric vs Imperial: Consider your work requirements carefully. Engineering drawings in the UK increasingly use metric dimensions, but many legacy machines and American equipment still work in imperial measurements. Some professionals opt for dual-scale rules or maintain both metric and imperial sets for maximum versatility.

Rule Length: Standard combination sets come with 150mm (6"), 300mm (12"), or occasionally longer rules. A 300mm rule offers greater reach and versatility for most applications, whilst a 150mm set provides excellent portability for toolbox storage and site work where space is limited.

Number of Pieces: Entry-level 4-piece sets typically include a rule, square head, centre head, and protractor. More comprehensive 5 or 6-piece sets may add a spirit level, scriber point, or additional attachments. Consider which heads you'll actually use – many professionals find the square and centre heads most valuable for daily work.

Quality and Accuracy: Precision combination sets from manufacturers like Moore and Wright offer superior accuracy (often guaranteed to within 0.001") with ground and hardened components. These represent a significant investment but will maintain their accuracy for decades. Mid-range options from Sealey and Faithfull provide excellent value for general workshop use, whilst budget sets suit occasional DIY applications.

Material and Finish: Look for stainless steel or hardened steel construction with satin chrome or black oxide finishes that resist corrosion. Stainless steel marking and measuring sets are particularly suitable for environments where rust prevention is important, such as marine engineering or outdoor site work.

Digital Options: Digital measuring sets, such as the Sealey AK9637D, incorporate electronic measuring instruments alongside traditional combination tools. These can speed up certain tasks and eliminate reading errors, though they require batteries and may be less suitable for harsh workshop environments.

Popular Accessories

• Engineer's Scribers: Hardened steel marking tools for scoring permanent reference lines on metal surfaces when used with combination set heads
• Centre Punches: Work alongside the centre head to mark drilling points accurately before machining operations
• Vernier Callipers: Complement combination sets by providing precise internal, external, and depth measurements to 0.01mm accuracy
• Micrometers: For even finer measurements alongside combination set layout work, particularly in precision engineering applications
• Marking Out Fluid: Blue or red layout dye that makes scribed lines highly visible on bright metal surfaces
• Protective Cases: Purpose-made storage boxes that protect precision instruments from damage and keep sets organised in the toolbox
• Gauge Blocks: Reference standards for checking and calibrating measuring equipment, ensuring ongoing accuracy
• Surface Plates: Flat reference surfaces for precision marking out and measurement verification in the workshop

Safety Information

Whilst combination sets are hand tools with minimal inherent safety risks, observing proper practices ensures accurate work and prevents damage to precision instruments:

• Always clean measuring surfaces before use – chips, swarf, or dust between the tool and work piece will cause inaccurate readings
• Handle with care to avoid dropping precision instruments, which can damage ground surfaces and compromise accuracy
• Keep graduated rules and measuring heads away from grinding wheels, welding spatter, and other heat sources that may affect calibration
• Use appropriate eye protection when scribing or marking metal surfaces to prevent metal particles entering the eyes
• Store combination sets in protective cases or dedicated toolbox compartments to prevent damage from other tools
• Avoid over-tightening locking screws, which can damage threads or distort components, affecting accuracy
• Apply a thin film of light oil to steel components periodically to prevent corrosion, particularly in damp workshop environments

Frequently Asked Questions

What's the difference between a combination set and a combination square?
A combination square typically consists of just a rule and square head, sometimes with a centre head. A combination set is more comprehensive, usually including a square head, centre head, and protractor head, making it a more versatile tool kit for diverse measuring and marking tasks. The set provides all the functionality of a combination square plus additional capabilities for angle measurement and centre finding.

How do I check if my combination set is still accurate?
Test the square head against a known straight edge or engineer's square – it should show no light gap when held against a perpendicular surface. For the centre head, test it on a cylinder of known diameter and verify it finds the true centre consistently. The protractor can be checked against gauge blocks or a known accurate angle plate. If you notice any discrepancies, the set may need professional recalibration or replacement.

Can I use a combination set for woodworking as well as metalworking?
Absolutely. Whilst combination sets are engineering tools primarily designed for metalwork, they're equally valuable for precision woodworking, cabinetmaking, and joinery. The hardened steel construction makes them more durable than woodworking-specific squares, though you should still protect them from excessive moisture and clean off any sawdust after use to maintain accuracy.

What maintenance do combination sets require?
Keep all components clean and free from debris – use a lint-free cloth and occasionally a light solvent to remove built-up grime. Apply a thin film of light machine oil or WD-40 to prevent rust, particularly on non-stainless steel components. Store in a dry environment, preferably in the original case or a dedicated toolbox section. Avoid dropping the set or allowing heavy objects to rest on it, as this can damage the precision ground surfaces.

Are expensive precision combination sets worth the investment?
For professional engineers, toolmakers, and machinists, premium sets from manufacturers like Moore and Wright available from Tooled-Up represent excellent value over time. They maintain accuracy for decades with proper care, whilst cheaper alternatives may lose precision through wear or were never manufactured to tight tolerances in the first place. For occasional DIY use or less critical applications, mid-range options from Faithfull or Sealey offer a good balance of quality and affordability.