Miscellaneous Helpful Information
Gun Drilling: The Steel Supply Company offers gun drilling services on through or blind drill requirements. The standard tolerances for gun drilling require .001" of concentricity/drift per 1" of depth. When items are drilled from both ends, there is the possibility of a slight mismatch at the center of the shaft. All bar materials, including Electreat products, may be gun drilled. A drawing is generally required for quotation purposes.
Tube Ovality: Ovality is defined in ASTM A513 for DOM tubular products and in A519 for Seamless tubular products. It should be noted also that when the wall thickness is less than 3% of the diameter additional ovality should be expected. This is especially apparent in thin wall Chrome Plated I.D. tube products.
Hardness: Alloy bars are only offered in the quench & temper, stress relief annealed condition. Annealed only items are not carried. Precipitation Hardness is limited to Type 630 Stainless Steel – also known as 17-4PH, and is carried only in Condition H-1150.
Straightness: The producing mills will only produce materials to the applicable ASTM straightness limits. As a processor, we require closer than standard straightness in order to grind or hone. Operations that affect bar straightness include induction hardening and certain milling operations such as keyways. Tube straightness exceeds bar tolerances and often requires a straightness process in order to properly process the material. While we do our best to offer special straight material, we can only guarantee those limits established by the ASTM or Producing Mill specifications.