Establish The Reference Before The Cut

A finished component can only be as dependable as the references used to make it. Starrett machinists tools give Australian machinists, toolmakers, fitters, maintenance crews & engineering workshops practical equipment for locating, marking, positioning, checking & setting up metalwork before machining makes the result permanent. Combination squares, surface gauges, scribers, punches, edge finders, V-blocks plus setup tools each solve a different workshop problem, from finding the centre of round stock to locating a milling-machine spindle against a workpiece.

For instruments used after setup to verify dimensions, explore Starrett | Micrometers. When those precision tools return to the bench, Starrett | Tool Storage & Cases provides related storage for protecting measuring equipment between jobs.

What Are Starrett Machinists Tools?

Machinists tools connect the drawing to the workpiece.

Some establish a datum. Others transfer dimensions, locate centres, create layout marks, support cylindrical components or help position a machine relative to the job.

Starrett's current Precision Shop Tools family includes equipment such as:

► Surface gauges
► Scribers
► Edge & centre finders
► Punches plus punch sets
► Tap wrenches
► Pin vises
► Vises plus clamps
► V-blocks
► Precision blocks plus angle plates
► Sine bars
► Toolmakers' hammers
► Bench blocks plus setup equipment

Alongside these sit Starrett precision squares, rules plus related measuring equipment used extensively by machinists.

The tools are mechanically simple compared with modern machine controls, but their functions remain fundamental: find the reference, establish the position, secure the setup then verify the work.

Why Choose Starrett Machinists Tools?

Machining errors often begin before the machine starts.

A centre marked in the wrong position, an edge established from contamination or a component supported incorrectly can carry an error into every subsequent operation.

Starrett's heritage is closely tied to solving these workshop problems. Its combination square remains one of the clearest examples because a single graduated blade can work with different heads to perform several measuring plus layout functions.

A square head establishes 90° plus 45° references.

A centre head helps locate the centre of round work.

A protractor head adds angular measurement plus transfer.

Starrett also offers replacement combination square heads, blades, storage cases plus repair components, allowing an existing square system to be repaired, reconfigured or expanded rather than automatically replaced as a complete unit.

Elsewhere in the machinist's kit, a surface gauge transfers a reference from a precision-ground base, a scriber marks the work, an edge finder establishes machine position plus a V-block supports round stock.

Each tool earns its place by solving a specific reference or setup problem.

Common Applications

Manual Milling – Find The Workpiece Before Finding The Feature

Coordinates mean little until the machine knows where the work is.

Starrett edge finders are used in the traditional method of establishing spindle location relative to a workpiece. Once an edge has been found, the machinist can use that known relationship when positioning subsequent features.

Starrett's 827 Edge Finders can be used around flat or straight edges, shoulders, grooves, round work, studs, dowels, centre points plus scribed lines.

For workpieces requiring secure positioning during setup, Clamps & Vises provides complementary workholding equipment.

Toolroom Layout – Transfer A Datum From The Surface Plate

A surface plate provides the plane. The surface gauge carries that reference to the work.

Starrett surface gauges use precision-ground bases plus adjustable posts to transfer dimensions to or from a workpiece. Hardened scribers or test indicators can be attached depending on the task.

Typical work can include:

► Scribing from a known height
► Comparing surfaces
► Transferring dimensions
► Locating points relative to a reference plane
► Supporting inspection setups

A chip beneath the gauge base changes that relationship immediately, making clean reference surfaces essential.

For broader marking plus dimensional work, Measuring & Layout Tools complements this type of bench setup.

Metal Fabrication – Make The Layout Line Worth Following

A narrow mark can carry a large consequence.

Starrett scribers use hardened points to physically mark fine lines, arcs, circles or angular references on suitable workpieces. In metalworking, this provides a defined physical reference where a broad marker or pencil line may be inappropriate.

Layout dye can increase visibility by creating contrast behind the scratched line.

The scriber does not establish accuracy by itself. The datum, measuring tool plus operator establish the location; the scriber records it on the work.

Drilling – Give The Tool A Starting Position

A drill meeting a smooth metal surface can wander before it begins cutting properly.

Punches provide a physical location for subsequent operations, but different punch styles serve different workshop purposes.

A sensible drilling sequence is:

► Establish the datum
► Measure the required position
► Scribe the intersecting references where appropriate
► Apply the correct punch
► Secure the workpiece
► Check alignment
► Begin drilling

For cutting, grinding plus subsequent metalworking operations, Metal Cutting & Grinding Tools provides related workshop equipment.

Shaft & Round-Stock Work – Stop Guessing At The Centre

Cylindrical components create reference problems that flat work does not.

A Starrett combination-square centre head places the blade across round work so intersecting lines can be used to establish the centre.

Where the component is not perfectly round, Starrett recommends creating several intersecting lines rather than assuming two marks will identify one perfect point.

V-blocks solve another cylindrical-work problem by supporting round material on controlled contact surfaces.

This relationship makes centre heads plus V-blocks particularly useful around shafts, pins, bushes, rollers plus other turned components.

Maintenance & Repair – Recreate What Already Exists

Repair work rarely begins with a pristine blank plus complete manufacturing drawing.

A maintenance fitter may need to reproduce an existing hole position, establish a centre, compare two surfaces or transfer the geometry of a worn component before repair can continue.

Squares, scribers, punches, surface gauges plus rules allow the existing assembly to become the reference.

For wider checking requirements around industrial maintenance, Testing & Measurement Tools supports related workshop inspection plus diagnostics.

Product Selection Guide

Start with the reference you need to establish.

Several tools can naturally appear in the same operation.

A machinist might establish a dimension from a datum, mark it with a scriber, punch the intersection, secure the component then machine the feature.

The correct purchase therefore depends on the operation surrounding the tool, not merely the tool's name.

Comparison Guide – Square, Surface Gauge, Edge Finder Or V-Block?

Four common tools can solve four completely different reference problems.

A tool that is excellent at one reference problem should not be expected to solve another.

Starrett Combination Squares – Build The System Around The Blade

A combination square becomes especially useful when treated as a configurable system rather than a fixed square.

Starrett combination squares use a hardened, graduated steel blade with an adjustable head. Depending on configuration, the same basic system can support square, centre plus protractor functions.

The Starrett C11H-12-4R is a useful example. This 12" combination square uses a satin-chrome blade with 4R graduations plus a cast-iron square head. Starrett identifies the blade as CB12-4R.

That model-specific relationship creates useful replacement options when one component needs attention.

Starrett's current combination-square accessory range includes:

► Replacement blades
► Square heads
► Centre heads
► Protractor heads
► Storage cases
► Repair components

For someone searching for a Starrett combination square replacement blade, the important questions are not simply blade length. Graduation pattern plus compatibility with the existing head matter too.

Likewise, a buyer looking for a Starrett combination square head should identify the square family before selecting the replacement.

Centre Heads – Find The Middle Of Round Work

A centre head changes the role of the combination-square blade.

Instead of establishing 90°, the head positions the blade across the face of cylindrical or square work so a line can be drawn through its centre region.

Rotate the tool around the component then make another intersecting line.

Where those lines meet indicates the centre.

Starrett currently identifies centre-head options including C11-4, C33-4, C11-6, C33-6, C11-1224 plus C33-1224, with cast-iron plus hardened-steel configurations available across relevant square families.

This creates useful buying distinctions between:

► Starrett centre head
► Starrett replacement centre head
► Centre finder for round stock
► Combination square centre attachment
► Centre head for shafts
► Centre head for machinist layout

These are highly specific workshop requirements rather than generic measuring-tool searches.

Protractor Heads – Add Angular Layout To The Combination Square

Some components need an angle rather than a right angle.

Starrett combination-square protractor heads allow the blade to rotate against a graduated protractor scale. Current Starrett guidance distinguishes between reversible plus non-reversible protractor-head designs.

A complete combination set can therefore bring together:

► Blade/rule
► Square head
► Centre head
► Protractor head
► Storage case

The Starrett 9ME-300, for example, is a current 300 mm combination set using square, centre plus non-reversible protractor heads around a metric/imperial blade.

For a machinist comparing a complete set against an individual square, the practical question is whether centre-finding plus angular layout will be used often enough to justify keeping all three heads available.

Surface Gauges – Carry The Reference Up From The Bench

A surface gauge is most useful when the work starts from a dependable plane.

Starrett describes its surface gauges as tools primarily used to extend a reference from a precision-ground base. They are typically used with a direct measuring tool to transfer a dimension to or from the workpiece.

Hardened scribers plus test indicators can serve as transfer contacts.

That supports tasks such as:

► Layout from a surface plate
► Comparison checks
► Height transfer
► Scribing parallel references
► Identifying specific points in space

A surface gauge for machinist layout therefore serves a different role from a combination square even though both can participate in marking operations.

Edge Finders – Establish The Milling Reference

Before machining a feature from an edge, the machine needs to know where that edge is.

Starrett's 827 Edge Finders are designed for locating work surfaces during traditional machine setup. Their bodies plus contacts are manufactured from hardened tool steel, with contact surfaces ground plus lapped for dimensional control.

Starrett also offers the S828 Wiggler/Center Finder set, which uses interchangeable attachments for different locating tasks.

Typical search requirements around this family include:

► Starrett edge finder
► Edge finder for milling machine
► Starrett 827 edge finder
► Centre finder for mill
► Wiggler centre finder
► Edge finder for round work

These searches indicate a buyer who already understands the setup problem, making clear application information especially useful.

V-Blocks – Control Round Work During Setup & Inspection

Round stock needs support that understands its geometry.

Starrett V-blocks use V-shaped contact surfaces to locate cylindrical or suitable square work while distributing clamping forces.

The Starrett 566 Dual-Vee Magnetic V-Block provides a concrete example. Starrett specifies two precision V surfaces for round stock from approximately 6.4–44 mm diameter, with a switch-controlled permanent magnet plus precision-ground working surfaces.

Its applications include general workshop layout plus holding suitable stock during light-duty milling, drilling or grinding.

That makes phrases such as Starrett magnetic V-block, V-block for round stock, machinist V-block with clamp plus V-block for shaft inspection useful distinctions within the wider machinists-tool category.

Sine Bars & Setup Blocks – When The Reference Is An Angle Or Known Height

Not every setup begins from an edge.

Starrett's 500 Sine Bar is designed for precise angular measurement plus positioning a working surface to a required angle. It is intended for use with suitable gauge blocks to establish the required geometry.

Precision blocks solve another setup problem by providing known physical dimensions for positioning or supporting work.

The practical distinction is:

Edge finder → establishes machine position from the workpiece.

V-block → supports cylindrical work.

Setup block → provides known physical geometry.

Sine bar → establishes a controlled angular relationship.

Understanding those roles prevents a broad machinists-tool collection from becoming a catalogue of unrelated steel objects.

Expert Tips

Clean every reference surface first. A chip beneath a square, V-block, setup block or surface-gauge base can compromise the setup before measurement begins.

Identify the combination-square family before replacing parts. Blade length alone does not establish compatibility; check the head series plus graduation requirements.

Use several centre lines on imperfect round stock. Multiple intersections provide more information when a shaft or component is not perfectly cylindrical.

Keep scriber marks fine. Heavy-handed marking can make the intended reference less clear rather than more accurate.

Select the punch for its actual job. Transfer, centre plus drive punches are not interchangeable simply because their shapes appear similar.

Protect precision-ground setup surfaces. V-blocks, squares plus gauge bases should not travel loose beside files or abrasive equipment.

Pick up machine edges deliberately. Edge finders establish a relationship between spindle plus workpiece; follow the correct machine setup procedure rather than treating contact as the final coordinate.

Check accessory compatibility before rebuilding a square. Starrett offers blades, heads plus repair components, but the existing combination-square series should be identified first.

Trades developing their first serious workshop kit can find broader equipment-selection context in The Apprentice's First Tool Kit: What You Actually Need.

Build The Process Around The Datum

The most useful machinists tools form a sequence rather than a random drawer of equipment.

Drawing → datum → measurement → layout → workholding → machining → inspection

The square establishes relationships.

The centre head finds the middle.

The surface gauge transfers the reference.

The scriber records the position.

The punch gives the next operation a physical starting point.

The edge finder relates the machine to the workpiece.

The V-block controls round material.

The measuring instrument checks what the process produced.

For experienced tradespeople, this chain becomes almost automatic. Whispers & Wisdom: We Are Losing the Art of the Master Tradesperson looks more broadly at the practical knowledge developed through years on the tools.

Equipment condition belongs in the same conversation. Spring Jobsite Prep Getting Your Gear Ready provides a useful reminder to check working equipment before workload increases.