Din 509-e0.6x0.2 -

Technical Data Sheet: DIN 509 E 0.6 x 0.2 1. Standard Reference DIN 509 (obsolete, replaced by DIN 509 – but often still used in drawings) specifies undercuts for screw threads and for machining cylindrical parts with subsequent grinding or thread rolling. 2. Designation Breakdown

E = External undercut (on a shaft) 0.6 = Nominal width of the undercut in mm (measured axially) 0.2 = Depth of the undercut in mm (radial depth from the cylindrical surface)

3. Geometry & Dimensions (per DIN 509:1998) | Parameter | Value | |-----------|-------| | Width b | 0.6 mm | | Depth t | 0.2 mm | | Radius r (bottom) | 0.1 mm (typically max) | | Transition angle | ~45° at shoulders (if specified) | 4. Purpose

Allows a grinding wheel to run out when grinding adjacent diameters. Provides clearance for thread cutting tools or thread rolling dies . Prevents stress concentration compared to a sharp internal corner. Ensures proper seating of parts against a shoulder. Din 509-e0.6x0.2

5. Typical Application

Small precision shafts, watchmaking components, miniature bearings, hydraulic valves, or medical instruments. Used where space is very limited (undercut width only 0.6 mm).

6. Manufacturing

Produced by turning (grooving tool) or form tool . Depth of 0.2 mm requires rigid machining and sharp tooling.

7. Important Notes

Not identical to ISO 4755 (which has different radii and depth definitions). Always confirm whether the drawing refers to old DIN 509 (pre-1998) or replaced versions – though the E 0.6x0.2 format is unambiguous. Technical Data Sheet: DIN 509 E 0

8. Potential Issue

A 0.2 mm depth on a 0.6 mm width creates a relatively steep groove – stress concentration may remain; a larger radius would be better if design permits.