SEBO Screw F 3.9 x 13 (DIN 968) for ET-1, ET-2 and SOFTCASE

Two DIN 968 screws share the ET parts list and the difference between them is eight millimetres of thread. This is the 13 mm one, part 1021, fitted on the ET-1 and ET-2 power heads and on the SOFTCASE. Both carry the collared cross-recessed pan head that the standard defines, a flange under the head that widens the bearing surface so the screw does not sink into the plastic under vibration.

Because that head form matches its longer relative exactly, these two get mixed up on the bench more often than any other pair in the box. The giveaway comes on final tightening: the right screw pulls the joint flat and stops, the wrong one either bottoms out early or spins on in a hole it was never meant to reach.

• Part number: 1021
• Fits: SEBO ET-1, ET-2 and SOFTCASE
• Specification: F 3.9 x 13 to DIN 968
• Head and drive: cross-recessed pan head with collar
• Size: 3.9 mm diameter, 13 mm long
• Sold: each
• Longer DIN 968 screw: part 1020 at 21 mm

Change one when the head has rounded out under a slipping driver, when the screw turns without clamping, or when a strip-down has left a casing screw missing. Keep a couple spare if you service ET heads regularly, as these are the ones that roll off a bench and disappear into a workshop floor.

A power head lives a harder life than the machine it hangs from. The brush roll runs inches away from every fastener in the casing, and the vibration that carries into the joints never stops while the machine is switched on. That is the reason SEBO specifies a collared screw here rather than a plain pan head, and the reason a casing screw is worth replacing rather than reusing once its recess has started to open up.

Anyone looking for a SEBO ET-2 casing screw, a SOFTCASE body screw or a genuine SEBO DIN 968 3.9 x 13 replacement wants this part number rather than the 21 mm version. Hold the old screw against the specification above before ordering. Genuine SEBO fastener from an authorized dealer, shipping in 2-5 business days.