Recursos/Machining Standards

Machining Standards & Specifications

Quick reference guide covering the most important international machining and engineering standards — from dimensional tolerances and surface texture to material testing and thread specifications.

Dimensional & Geometric Tolerances

General Tolerances - Linear & Angular

ISO 2768-1

Default tolerances for undimensioned drawing features. We follow ISO 2768-f (fine) class.

Applicable grades/classes:

General Tolerances - Geometric

ISO 2768-2

Flatness, straightness, parallelism, perpendicularity for undimensioned features.

Applicable grades/classes:

Limits & Fits - ISO System

ISO 286

Hole-basis and shaft-basis fit system. Commonly used fits: H7/g6 (sliding), H7/h6 (location), H7/p6 (press).

Applicable grades/classes:

GD&T Standard

ASME Y14.5

Geometric Dimensioning & Tolerancing per ASME for US-based customers. Both ISO and ASME GD&T supported.

Applicable grades/classes:

Surface Finish

Surface Texture Parameters

ISO 4287

Ra, Rz, Rmax measurement standards. Our default machined finish is Ra 0.8 um; achievable up to Ra 0.05 um.

Applicable grades/classes:

Surface Texture Indication

ISO 1302

Drawing symbol notation for surface finish requirements on engineering drawings.

Applicable grades/classes:

Thread Standards

ISO Metric Thread Tolerances

ISO 965

General purpose metric threads - 6H/6g tolerance class as standard. Precision threads to 4H/3B available.

Applicable grades/classes:

Unified Inch Screw Threads

ASME B1.1

UNC/UNF thread standard for US customers. Thread milling for precision classes.

Applicable grades/classes:

Inspection & Quality

CMM Verification

ISO 10360

Coordinate Measuring Machine accuracy verification and acceptance testing.

Applicable grades/classes:

Hardness Testing Standards

ISO 6506/6507/6508

Brinell (HB), Vickers (HV), and Rockwell (HRC/HRB) hardness testing methods.

Applicable grades/classes: