Starrett

The Starrett collection spans seven precision measurement categories across 25+ instruments. Indicators include the 716 Series dial test indicator, the 811 Series swivel-head dial test indicator sets, the 656-6041J long-range dial indicator, the 2900-1-1 electronic indicator, the 653 and 653G comparator stands, the S668CZ/S668DZ shaft alignment clamp sets, and the 1175Z groove gage. Micrometers include the ST436.1CXRLZ and ST436.1CXFLZ inch outside micrometer sets (0–6"), the S436MEXRLZ metric outside micrometer set (0–150mm), and the 486P-10 blade-type micrometer (9–10"). Precision rules and reference tools include the C404R-72, C416R-48, C416R-72, C635-1800MM, CH416R-72 hook rule, 385-72 straight edge, and 20-12 and 20-24 master precision squares. The 199Z master precision level, the SR160 surface roughness tester, and the 3811A portable hardness tester complete the lineup. L.S. Starrett Company, founded in 1880 in Athol, Massachusetts, has been manufacturing precision tools for over 140 years.

L.S. Starrett Company was founded in 1880 by inventor Laroy Sunderland Starrett, who patented the sliding combination square, a design that remains a shop standard to this day. The company produces over 5,000 variations of precision tools, gauges, measuring instruments, and saw blades from its Massachusetts headquarters. Starrett's reputation is built on three principles that have held for over a century: high-grade materials (hardened and tempered steel, carbide-tipped measuring faces, jeweled bearings), manufacturing precision (ground, lapped, and satin-chrome finished surfaces), and long service life. A Starrett tool purchased today is engineered to perform identically for decades of daily shop use making their instruments frequent choices for aerospace, automotive, defense, toolmaking, and quality control environments where reliability is not negotiable.

Three micrometer sets cover different unit systems and application types. The ST436.1CXRLZ (0–6", ratchet stop) and ST436.1CXFLZ (0–6", friction thimble) are both inch outside micrometer sets covering the standard 0–6" range in six individual instruments, the difference is the thimble mechanism, with the ratchet stop providing a consistent, repeatable measuring force for production environments, and the friction thimble offering a smoother, operator-controlled feel preferred in toolroom and inspection use. The S436MEXRLZ covers 0–150mm in 25mm steps for metric-system environments. All three sets feature carbide-tipped measuring faces for long wear life, satin-chrome thimbles for glare-free readability, rigid balanced frames, ratchet or friction stops, lock rings, and included setting standards for field calibration the complete configuration for professional daily use.

The Starrett 199Z is a laboratory- and shop-grade master precision level with a 15" (380mm) precision-ground base and an extremely sensitive vial designed for ultra-precise leveling, alignment, and surface plate inspection. Its reversible vial design allows comparative readings placing the level in one orientation, reading the vial, then reversing it 180° and reading again to verify or cancel any residual vial error and confirm true level. The 199Z is the appropriate tool for machine tool installation and alignment (ensuring a lathe bed or machining center has no twist), surface plate flatness checks, alignment of critical rotating equipment foundations, and precision metrology lab setups where a tilt of even a few arc-seconds affects measurement validity. It is not a general construction level but it is a metrology reference instrument.

The Starrett 1175Z is a dial indicator groove gage designed specifically for in-process and bench inspection of internal grooves such as oil grooves, snap ring retainer grooves, O-ring seat retainer grooves, and similar recesses that no standard bore gauge, caliper, or micrometer can measure directly. Its movable contact has a 0.5" (12.7mm) retractable range transferring through a linear, friction-free mechanism to the dial indicator, reading to 0.0005" over a total range of 0.060". Two sets of interchangeable jaws cover gauging depths to 1.25" and 2.50", and three sets of interchangeable contacts address bore diameters from 0.375" to 6.00" with groove depths of 0.100" to 0.265" and groove widths as narrow as 0.024". The fixed lower reference jaw supports the full weight of the gage and the operator's hands, eliminating incorrect gaging pressure which is a common source of error in groove measurement. It is also used for checking bore dimensions and detecting taper, bell-mouth, and out-of-roundness.

The Starrett 3811A is a Leeb (dynamic) digital portable hardness tester using a D impact device, designed specifically for testing large, heavy ferrous parts that cannot be brought to a benchtop tester for large forgings, structural steel, heavy castings, installed machinery, pressure vessels, and heavy fabrications. Its ±0.5% accuracy (referenced to L=800) and measuring range of 200–960 HL are appropriate for steel, cast steel, alloy tool steel, stainless steel, grey cast iron, spheroidal iron, cast aluminum, brass, bronze, and wrought copper alloys. Results automatically convert to Rockwell B and C, Brinell, Vickers, and Shore scales. The 3811A includes USB output and built-in memory for test data logging and documentation. It is simple to operate, first load the impact body, place the device on the test surface, and press the button. Support rings for curved surfaces (minimum convex radius 30mm, or 11mm with ring) are available as accessories for testing cylindrical parts in the field.

The Starrett SR160 is a shop-hardened portable surface roughness tester with a protected piezoelectric diamond-tip stylus, a color on-screen graph display showing multiple parameters simultaneously, and two-piece Bluetooth connectivity for wireless data output. It is shock-tested and engineered to withstand the physical demands of production shop floors and not just controlled lab environments. The rechargeable lithium-polymer battery delivers over 10,000 measurements per charge, eliminating battery anxiety in high-volume inspection programs. Both skidded and skidless measurement modes are supported. The parameter set includes Ra, Rz, Rp, Rv, Rt, RZ1Max, Rsk, Rq, Rku, Pa, Pz, Pp, Pv, and Pt which are one of the broadest parameter sets available at this portability tier, covering every major ISO, DIN, JIS, and ANSI surface texture parameter likely to appear on an engineering drawing specification.

The Starrett S668CZ and S668DZ are precision shaft alignment clamp sets that mount directly to rotating shafts to hold a dial indicator in a secure, repeatable position for machinery alignment and runout inspection. The clamp attaches to the shaft and positions the indicator contact against a reference surface and the shaft is then rotated manually and total indicator runout (TIR) is read directly from the dial. This is the standard method for checking coupling alignment on motors, pumps, gearboxes, and power transmission shafts; measuring spindle runout on lathes and machining centers; verifying journal concentricity; and setting up bearing bores. The S668DZ offers an extended configuration for larger shaft diameters or deeper-reach requirements compared to the S668CZ, while both provide the rigid, precise indicator mounting that accurate alignment demands.

The Starrett 20-12 (12" blade, ~8" beam) and 20-24 (24" blade) are non-adjustable master precision squares manufactured to ±0.0001" squareness accuracy per 6" the highest achievable standard for a fixed-reference square. Both are hardened, ground, and lapped steel with precision-lapped edges, satin finish, and a factory inspection certification. In machine tool environments, they are used to verify and calibrate other squares, check the squareness of machine spindles relative to the table, align vise jaws to the column, and set up workholding fixtures to confirmed 90°. In quality labs, they serve as the traceable reference from which all other squareness checks in the shop are validated. The 20-24 is the right choice when the feature height to be checked exceeds the reach of a 12" blade, large vertical machining center columns, tall fixture bodies, structural plate assemblies, and press brake tooling setups all typically require 24" blade reach.

All Starrett orders ship free to the continental USA on orders and backed by a best-price guarantee. A 30-day return policy and Affirm financing at checkout are available across the full Starrett lineup. Government agencies, calibration labs, and defense contractors can submit an RFQ through the dedicated Government RFQ page (DUNS: 13-715-2209, CAGE: 15F67). Starrett's product lineup spans from everyday shop rules to master metrology reference tools by selecting the right model, unit system, measuring range, and thimble configuration involves decisions that interact with the application and the existing instrument fleet. Gustavo personally reviews every order and is available to help buyers choose the right Starrett instrument before purchasing simply call or text 617-398-7852, Monday through Friday, 8am–5pm EST.