GN 6339

Washers for heavy duty applications

SKU: 8285 Category:
To request 2D/3D drawings, click on the RED code/desc in Product Details below.
Technical Drawing

Additional information

Chamfer angle α = 70° ± 2°

This relatively large angle is necessary when using hexagon headed bolts, which usually have a tapered transfer from shank to head (the so-called trumpet) to avoid fouling of the washer.

Chamfer edge F

The extended chamfer side F as seen from d<SUB>2</SUB> creates with d<SUB>1 </SUB>an edge the so-called trumpet of the transfer from shank to head of the bolt, so that the smallest radial clearance prevails. Even with the smallest angle of 68° and the lower dimension of d<SUB>2 </SUB>and d<SUB>1 </SUB>the radial clearance of all bolts to DIN EN is still sufficient.

Chamfer face diameter d2

This dimension is, together with the chamfer angle α 70° and the inside diameter d<SUB>1</SUB>, the most important dimension of these heavy duty washers. Diameter d<SUB>2</SUB> is actually, even in the lower tolerance range, larger than the max. contact under head diameter on a bolt. This will ensure that the chamfer of d<SUB>2</SUB> of the hardened washer will not be pressed into the underhead radius causing an indentation on the bolt which would damage the bolt.

Features and applications

The influence of a washer on the quality of the screwed connection is very often understimated. With washers GN 6339, high quality preloaded screwed connections can be established. A high static clamping force can be reached avoiding loss of tension.<BR>At a specified preloaded clamping force it is often possible to use thinner bolts. This can result in a better ratio between clamping distance and bolt diameter to minimise the danger of failure.<BR>The case hardened smooth bolt head/screw contact face leads to a lower and more constant friction coefficient even when continuous clamping and releasing operations are required.<BR>Washers GN 6339 are only suitable for machine construction bolts of classes 8.8 / 10.9 / 12.9, and not for steel bolts DIN 6914.

Inside diameter d1

The inside diameter d<SUB>1 </SUB>is kept as small as possible ensuring that the bolt is inserted centrically into the washer. The choice of a matching pair of bolt and washer with least radial clearance is important in order to avoid a mismatch between chamfer diameter d<SUB>2 </SUB>and the max. contact area diameter of the bolt head.

Lead height h2

This is the height of the cylindrical part of the internal diameter d<SUB>1</SUB>, h<SUB>2</SUB> should be as high as possible in relation to the pitch of the thread of the bolt.

Material

– Version <STRONG>BT</STRONG>: case hardened black oxide steel, material-no. 1.7227, fine machined and fine ground, tensile strength Rm = 1220 – 1400 N/mm<SUP>2</SUP>.<BR>- Version <STRONG>GO</STRONG>: case hardened steel treated GEOMET 500, material-no. 1.7227, fine machined and fine ground, tensile strength Rm = 1220 – 1400 N/mm<SUP>2</SUP>.

Outside diameter D

The outside diameter D of the lower refers to washers DIN 125 / ISO 7089, and the higher type to washers DIN 7349.

Washer thickness L

Washers GN 6339 are higher when compared with DIN washers (exception: DIN 7439 which is equal to the high type). A larger thickness leads to a stronger washer. As a result, bearing in mind the chamfer d<SUB>2</SUB>, a minimum height is established which ensures that the bolt thread will not be damaged when the bolt is tightened.

Additional Technical Drawing

Product Details

Standard Elements Main dimensions for threaded bolts Weight
Description d1 H13 D h13 d2 H13 l1 ±0.2 L ±0.2
GN 6339-6.3-12-2.5-BT 6.3 12 7 0.6 2.5 M6
GN 6339-6.3-17-3-BT 6.3 17 7 1 3 M6
GN 6339-8.4-16-2.5-BT 8.4 16 9.5 0.75 2.5 M8
GN 6339-8.4-21-4-BT 8.4 21 9.5 1.5 4 M8
GN 6339-10.4-20-3-BT 10.4 20 11.5 0.75 3 M10
GN 6339-10.4-25-4-BT 10.4 25 11.5 1.5 4 M10
GN 6339-12.5-24-3.5-BT 12.5 24 14 1 3.5 M12
GN 6339-12.5-30-6-BT 12.5 30 14 2 6 M12
GN 6339-14.5-28-3.5-BT 14.5 28 16 1 3.5 M14
GN 6339-14.5-36-6-BT 14.5 36 16 2 6 M14
GN 6339-16.5-30-4-BT 16.5 30 18 1 4 M16
GN 6339-16.5-40-6-BT 16.5 40 18 2 6 M16
GN 6339-18.5-34-5-BT 18.5 34 21 1.5 5 M18
GN 6339-18.5-44-8-BT 18.5 44 21 2.5 8 M18
GN 6339-20.5-37-5-BT 20.5 37 23 1.5 5 M20
GN 6339-20.5-44-8-BT 20.5 44 23 2.5 8 M20
GN 6339-22.5-40-5-BT 22.5 40 25 1.5 5 M22
GN 6339-22.5-50-8-BT 22.5 50 25 2.5 8 M22
GN 6339-24.5-44-5-BT 24.5 44 27 1.5 5 M24
GN 6339-24.5-50-10-BT 24.5 50 27 3.5 10 M24
GN 6339-28-50-6-BT 28 50 31 1.5 6 M27
GN 6339-28-60-10-BT 28 60 31 3.5 10 M27
GN 6339-31-56-6-BT 31 56 34 1.5 6 M30
GN 6339-31-68-10-BT 31 68 34 3.5 10 M30
GN 6339-37-66-7-BT 37 66 40 2 7 M36
GN 6339-6.3-12-2.5-GO 6.3 12 7 0.6 2.5 M6
GN 6339-6.3-17-3-GO 6.3 17 7 1 3 M6
GN 6339-8.4-16-2.5-GO 8.4 16 9.5 0.75 2.5 M8
GN 6339-8.4-21-4-GO 8.4 21 9.5 1.5 4 M8
GN 6339-10.4-20-3-GO 10.4 20 11.5 0.75 3 M10
GN 6339-10.4-25-4-GO 10.4 25 11.5 1.5 4 M10
GN 6339-12.5-24-3.5-GO 12.5 24 14 1 3.5 M12
GN 6339-12.5-30-6-GO 12.5 30 14 2 6 M12
GN 6339-14.5-28-3.5-GO 14.5 28 16 1 3.5 M14
GN 6339-14.5-36-6-GO 14.5 36 16 2 6 M14
GN 6339-16.5-30-4-GO 16.5 30 18 1 4 M16
GN 6339-16.5-40-6-GO 16.5 40 18 2 6 M16
GN 6339-18.5-34-5-GO 18.5 34 21 1.5 5 M18
GN 6339-18.5-44-8-GO 18.5 44 21 2.5 8 M18
GN 6339-20.5-37-5-GO 20.5 37 23 1.5 5 M20
GN 6339-20.5-44-8-GO 20.5 44 23 2.5 8 M20
GN 6339-22.5-40-5-GO 22.5 40 25 1.5 5 M22
GN 6339-22.5-50-8-GO 22.5 50 25 2.5 8 M22
GN 6339-24.5-44-5-GO 24.5 44 27 1.5 5 M24
GN 6339-24.5-50-10-GO 24.5 50 27 3.5 10 M24
GN 6339-28-50-6-GO 28 50 31 1.5 6 M27
GN 6339-28-60-10-GO 28 60 31 3.5 10 M27
GN 6339-31-56-6-GO 31 56 34 1.5 6 M30
GN 6339-31-68-10-GO 31 68 34 3.5 10 M30
GN 6339-37-66-7-GO 37 66 40 2 7 M36