Crown Windley Metrology Standards

Eley Metrology's granite metrology standards range has incorporated the expertise of the Crown Windley name to ensure the highest quality products for customers. Our granite metrology standards are hand-lapped by our highly skilled precision engineers in accordance with the specified standards. Eley can also recondition your granite standards back to their original specification.


Precision Granite Squares

Made from the same high quality granite that our tables are produced from, our precision squares are unrivalled in strength. Hand lapped using diamond by our precision engineers in accordance with BS 939 (2007) to either laboratory (Grade AA) or inspection grade (Grade A). Master squares can be used to for inspecting X, Y and Z axes of machine tools. Checking squareness, straightness and parallelism is also a benefit of precision master squares. 6 finished faces and the ability to produce a square with lifting holes means that Eley Metrology are the number one choice for granite metrology standards with rigorous testing environments and the highest quality granite.

Precision Granite Straight Edges

Eley's straight edges are produce from black granite and can be produced with either one or two master faces. Hand finished straight and parallel in accordance with BS 5204 Part 2 (1977) to laboratory (Grade AA) or inspection grade (Grade A), these straight edges can be provided with lifting holes, alongside detachable handles. Master or standard straight edges can be produced dependent upon their usage; the master version is produced with 2 master faces, and the standard with one. These straight edges are parallel on the 1 ½ ” or 2” face.

Precision Granite Tri-Squares

Produced from black granite and hand finished by precision engineers in our laboratory environment to accuracies in line with BS 939 (2007). Also available in laboratory (Grade AA) and inspection (Grade A) grades, Eley's tri-squares have two master faces; finished flat, square and perpendicular.