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Westfield Fasteners Product Specification:

DIN 439 - Half Nut (Lock Nut), Coarse Pitch

This product guide contains the specification for metric threaded half or lock nuts, a range of standard parts available from Westfield Fasteners. The basis of this specification is the DIN standard DIN 439.

Product Description

Hexagon thin, jam, locking or half nut with standard metric coarse pitch, but with a Left Handed Thread.

To DIN 439. Only for use in conjunction with Left Handed Thread bolts or screws.

Hexagon half nut with standard metric coarse pitch, but with a Left Handed Thread.

Two left handed half nuts can be used together to form a 'locking' formation, which is more secure than a full or single half nut alone.

Left handed half/thin hex nuts are also known as reverse nuts. Left handed nuts are typically used where a right handed nut would loosen with a rotational force.

Scope of the DIN standard.

DIN 934 (similar to ISO 4032) specifies the tolerances and the variation of detailing allowable for hexagonal half nuts, for sizes from M1 up to and including M160.

DIN 934 is for A2-70, A4-70 stainless steel and steel.

Notes to figure 1:

• Type A - up to and including M2.5 is 11 H. From M3 upwards, it's 04.
  
• Type B - up to and including M2.5 is 11 H. From M3 to M10, it's 04. M12 to M39, it's 04, 06. Over M39, it's 14 H.

Variations from DIN 985

DIN 439 covers materials including carbon steel and brass. The hex thin nuts we stock in other materials and grades are made with reference to this standard, but are not mentioned specifically.