ISO 9448-8:2013

Overview

ISO 9448-8:2013 - Tools for pressing - Guide bushes - Part 8: Form G, gliding bushes, stepped, type 1 specifies the principal dimensions, tolerances and basic requirements for stepped gliding guide bushes used in press tools. Dimensions are given in millimetres and the standard covers mounting by interference fit in the clamp plate over a specified length, with the remaining length providing the guiding function. Bushes include a clearance for lubrication and the standard gives guidance on material selection, hardness and part designation.

Key topics and technical requirements

• Dimensions & tolerances: Main dimensions and tolerances are defined by the standard’s Figure 1 and Table 1. Typical nominal guiding diameters listed include 12, 16, 20, 25, 32, 40, 50, 63, 80 and 100 mm.
• Fit & assembly: Guide bushes are intended to be press‑fitted into holes with a tolerance of H7; when glued, a tolerance of j6 is permitted to suit the application. Interference fit length and guiding length are distinguished in the geometry.
• Lubrication: Bushes are provided with a clearance for lubrication; specific groove/chamfer details are left to the manufacturer’s discretion.
• Material & hardness: Material selection is left to the manufacturer, but the hardness requirement is specified as 60 HRC (see ISO 6508-1 for Rockwell test methods).
• Manufacturing details: Chamfers, radii, lubrication grooves and surface finish values are not fully specified and may be chosen by the maker; surface roughness is referenced in micrometres.
• Designation: A standardized designation format is specified (for example: “Guide bush ISO 9448-8 G - 12 × 20”).

Applications and users

• Primary use: guiding punches, pins and sleeves in press tools and die sets where accurate axial alignment and controlled lubrication are required.
• Typical users: toolmakers, die designers, press tool manufacturers, maintenance engineers and procurement/specification specialists in metal forming, stamping and progressive die operations.
• Benefits: ensures interchangeability, predictable fits, consistent hardness for wear resistance and clear part identification for tooling inventories.

Related standards

• ISO 9448 (series) - other parts cover different forms (A–F, types 1 & 2) for plain, headed and flanged bushes.
• ISO 6508-1 - Metallic materials - Rockwell hardness test - referenced for verifying the 60 HRC hardness requirement.

Keywords: ISO 9448-8, guide bushes, form G, gliding bushes, stepped bushings, press tools, interference fit, H7, j6, 60 HRC, toolmaking.