Granite Straight Edges
Precision Reference Tools for Alignment, Flatness & Machine Calibration
Enquire NowProduct Overview
SPT Metrology manufactures Granite Straight Edges lapped to IS 7327-2003 standards for checking straightness, alignment, and flatness across machine tool guideways, assemblies, and inspection surfaces. As a trusted Granite Straight Edge Manufacturer, we build these from naturally seasoned black granite specifically as a stable, corrosion-free alternative to cast iron straight edges, a shift more tool rooms are making as granite technology matures.
Why Granite Replaces Cast Iron Here
A straight edge's entire job is holding an unwavering reference line, and that's exactly where cast iron's weaknesses show up over time: it rusts, it can develop burrs from handling, and it shifts slightly with temperature. Granite does none of this. It's non-magnetic, has minimal thermal expansion, and resists wear well enough that a granite straight edge purchased today can still be trusted years into daily use without re-verification anxiety.
Precision-Lapped for True Straightness
Every edge undergoes advanced lapping to achieve the straightness, flatness, and parallelism tolerances the standard demands, then passes stringent inspection before it ships. This finish quality is what allows sensitive instruments (feeler gauges, dial indicators, electronic levels, slip gauges) to take a reading off the edge and trust it completely, rather than second-guessing whether the reference itself has drifted.
Lighter to Handle, Still Rigid Enough to Trust
Granite's lower weight relative to an equivalent cast iron straight edge makes it noticeably easier to move and position during alignment work, without sacrificing the rigidity needed for accurate guideway or assembly checks. Available in rectangular, triangular, and parallel profiles to match different inspection applications.
Sizes & Configurations
Standard lengths cover most tool-room and machine-alignment needs, with custom lengths available for larger machine tool applications. Optional metal inserts or lifting handles can be added for easier handling without touching the reference surfaces themselves.
Why Manufacturers Choose SPT
As a Granite Straight Edge Supplier trusted across Tamil Nadu and beyond, we lap every edge to hold its straightness under real workshop conditions, not just under the controlled environment of a calibration lab.
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Granite Straight Edge Manufacturers Across India.
From our facilities in Chennai and Dharmapuri, we manufacture and supply granite straight edges to tool rooms and machine alignment specialists nationwide.