Mahr 107 MarStand Granite Surface Plate

Mahr 107 MarStand Granite Surface Plate The Mahr MarStand 107 G is Mahr's precision granite surface plate series is the reference datum foundation for height measurement, layout work, comparative gaging, and precision part lapping and finishing in metrology laboratories, quality control rooms, tool rooms, and production inspection environments. Manufactured from carefully selected fine-grain black Diabase granite and finished to DIN 876 flatness standards in three tolerance classes, Grade 00 (laboratory/master grade), Grade 0 (inspection grade), and Grade 1 (toolroom/production grade). The 107 G series covers measurements from the finest calibration room applications through general production floor quality control across eleven plate sizes from 400×250mm through 2000×1000mm. Diabase is a dark, fine-grain igneous rock chosen for precision surface plates because its densely interlocked crystal structure unlike the coarser, more porous composition of common granite which delivers a higher degree of material homogeneity, greater resistance to chipping at the working surface edges, and more uniform hardness across the lapped face. Mahr specifies the 107 G's Diabase at 6–7 on the Mohs hardness scale, placing it harder than most steels at the surface and making the working face highly resistant to wear, indentation, and embedding of abrasive particles from part contact. The close crystal arrangement also minimizes microscale surface voids that would allow coolants, cleaning fluids, or atmospheric moisture to penetrate below the lapped surface contributing to the plate's absolute corrosion resistance in metrology and production environments where carbon steel or cast iron references would require active rust prevention. The working surface of every 107 G is precision lapped to a silk-matt (satin) finish. This finish serves two distinct purposes: it provides the extremely flat, stable datum surface required for dimensional reference measurement, and it eliminates the high-gloss specular reflection of a polished granite surface that creates glare and reduces visibility of scribed lines, measuring tools, and instrument displays in the working area. The lapped finish also presents the densest, hardest layer of the granite to the working surface, maximizing wear life and flatness retention under the sustained point-contact loading of measuring instrument bases, height gage columns, and workpiece contact. The 107 G's non-magnetic and non-conductive material properties are operationally important in precision measurement environments: non-magnetic surfaces prevent measuring instruments, gage blocks, and workpieces from being held to the plate by residual magnetism which would distort height measurements by adding an unmeasured attractive force component and non-conductivity eliminates stray electrical grounding paths through the plate that could affect sensitive electronic measurement systems. The plate is also absolutely corrosion-proof, requiring only routine cleaning with a lint-free cloth and appropriate granite cleaner to maintain the working surface. Installation requirements scale with plate size. Plates up to 400mm in the shorter dimension are designed for workbench use with the 107 Asa adjustable three-point plate supports, which level the plate independently of the workbench surface flatness. Plates from 630mm and larger are intended for use with the 107 Us open stand or 107 Ug enclosed cabinet stand, both of which provide the structural rigidity, three-point leveling, and working-height ergonomics that large-format surface plate use requires. All plates are supplied with a certificate of accuracy documenting measured flatness against the applicable DIN 876 tolerance class. Key Features Selected Fine-Grain Black Diabase - The 107 G is manufactured from carefully chosen fine-grain Diabase granite rather than common coarse-grain granite, with a densely interlocked crystal structure that delivers higher material homogeneity, lower porosity, sharper and more durable working surface edges, and a Mohs hardness of 6–7 making the lapped surface exceptionally resistant to wear, indentation, and particle embedding under sustained point-contact loading from measuring instrument bases, gage blocks, and workpieces in high-cycle production inspection and precision measurement use. DIN 876 Certified in Three Tolerance Classes (Grade 00, Grade 0, and Grade 1) - Grade 00 (laboratory/master) is certified for gauge rooms, calibration laboratories, and master reference applications in temperature-controlled environments where the lowest achievable flatness deviation is required; Grade 0 (inspection) is certified for general quality control and incoming inspection; Grade 1 (toolroom/production) is certified for shop floor and production area use with every plate supplied with a certificate of accuracy documenting the measured flatness deviation against its applicable DIN 876 tolerance class for full traceability documentation. Silk-Matt Lapped Finish - The working surface is precision lapped to a silk-matt (satin) finish that eliminates the specular glare of polished granite while delivering the extreme flatness required for dimensional reference measurement; the lapped finish also presents the densest and hardest material layer to the working surface for maximum flatness retention and wear life, and the reduced surface reflectivity improves visibility of scribed layout lines, measuring instrument displays, and fine surface detail during height measurement and layout work under production lighting conditions. Non-Magnetic, Non-Conductive, and Absolutely Corrosion-Proof - The Diabase granite material carries no magnetic properties, preventing measuring instruments, gage blocks, and precision workpieces from being attracted to the plate surface by residual magnetism that would introduce unmeasured force components into height and comparative measurements; the non-conductive surface eliminates stray grounding paths through the plate that could affect sensitive electronic gaging and SPC systems; and absolute corrosion resistance eliminates the rust prevention, coating, and surface conditioning routines required by cast iron and carbon steel reference surface alternatives. Eleven Plate Sizes (400×250mm to 2000×1000mm) and Three Grades per Size - The 107 G series scales from 400×250mm (benchtop and portable instrument support) through 630×400mm, 630×630mm, 800×500mm, 1000×630mm, 1200×800mm, and 1500×1000mm to the large-format 2000×1000mm configuration for CMM staging, shaft layout, and large-assembly inspection with each size available in Grade 00, Grade 0, and Grade 1 to match the precision requirement and environment of the measurement application without over-specifying for production-floor use or under-specifying for laboratory and calibration applications. Matched Mahr Accessory Ecosystem (Plate Supports, Open Stand, and Enclosed Cabinet) - Plates up to 400mm are configured for workbench use with the 107 Asa three-point adjustable plate supports that level the plate independently of the workbench surface; plates from 630mm and above pair with the 107 Us open stand or the 107 Ug enclosed storage cabinet stand, both providing three-point leveling, structural rigidity, and optimized working height ensuring that every 107 G installation is supported, leveled, and ergonomically positioned for the measurement task rather than placed on improvised supports that compromise flatness and measurement repeatability. Specifications Material Properties Property Detail Material Fine-grain black Diabase (hard granite) Crystal Structure Densely interlocked with high homogeneity, low porosity Hardness 6–7 Mohs scale Surface Finish Silk-matt (satin) lapped and glare-free Magnetic Properties Non-magnetic Electrical Properties Non-conductive Corrosion Resistance Absolutely no surface treatment required Standard Compliance DIN 876 Complete Size and Weight Reference Plate Size (L × W) Thickness Approx. Weight Grade 00 Grade 0 Grade 1 400 × 250mm 60mm ~15 kg — 4221520 — 400 × 400mm 60mm ~24 kg — 4221521 — 630 × 400mm 80mm ~60 kg 4221502 4221522 4221542 630 × 630mm 80mm ~95 kg 4221503 4221523 4221543 800 × 500mm 100mm ~95 kg — 4221524 4221544 1000 × 630mm 100mm ~190 kg 4221505 4221525 4221545 1200 × 800mm 150mm ~430 kg 4221506 4221526 4221546 1500 × 1000mm 150mm ~680 kg — 4221527 4221547 2000 × 1000mm 200mm ~1,200 kg 4221508 4221528 4221548 Items Included Mahr MarStand 107 G granite surface plate (size and grade as specified) Certificate of accuracy - measured flatness documented against applicable DIN 876 tolerance class