Gauges & Protractors

A lathe center gauge features precise 60-degree V-notches along its edges, which
match standard metric and unified thread profiles. Machinists use it by resting one flat edge against a cylindrical workpiece and sliding their tool bit into the matching notch. This simple check ensures the tool's cutting edge sits perfectly square to the workpiece axis, ensuring uniform thread faces

A round head protractor features a full circular flat back that provides a wide, stable base against long straight edges, making it excellent for transferring layout lines across wide plates. A semi-circular protractor uses a compact 180-degree head design that fits more easily into narrow corners, deep pockets, or tight machine spaces where a full
circle would bind.

A satin-chrome finish creates a soft, matte look that scatters light, reducing bright reflections from overhead shop lamps. This glare reduction makes the fine, laser-etched graduation lines much easier to read, helping operators take fast, accurate measurements without eye strain or parallax errors.

Most professional combination sets, such as the Blue Fox Combination Pitch Gauge (52 Leaves), stamp the scale type directly onto each leaf. Metric leaves show the pitch distance in millimeters (e.g., 1.25mm), while imperial leaves display the thread count per
inch (e.g., 24G or 24 TPI), making it easy to tell them apart.

Yes, high-quality stainless steel protractors resist corrosion from standard water-soluble cutting fluids. However, you should still wipe them clean with a dry cloth at the end of every shift and apply a thin film of low-viscosity oil before storage to prevent
dried fluid residue from gumming up the pivot joints.

Loss of accuracy is typically caused by surface scratches, rounded corners from drop damage, or abrasive wear from sliding tools across rough castings or abrasive scale. Storing your tools carefully inside protective cases and deburring your workpieces before measuring will help preserve their precision edges.

Loss of accuracy is typically caused by surface scratches, rounded corners from drop damage, or abrasive wear from sliding tools across rough castings or abrasive scale. Storing your tools carefully inside protective cases and deburring your workpieces before measuring will help preserve their precision edges.

Yes, you can check internal threads by sliding a narrow pitch leaf into the tapped hole and checking how the teeth mesh against the internal thread walls. If the leaf fits perfectly without rocking or showing daylight between the gaps, you have identified the correct thread pitch.

An arc-minute is a fine angular measurement equal to 1/60th of a single degree. Protractors equipped with vernier scales can read down to fractions of a degree (),
providing the high precision needed to set up close-tolerance bevels and angled
fixtures accurately.

Avoid using coarse sharpening stones or aggressive files on precision scales, as they can easily grind away material and alter the flat reference surfaces. To clear light surface marks or stains, scrub the area gently with a fine polishing pad and a small amount of light oil.