• News Releases
• Events & Tradeshows

News >

Fasteners, Fastening Steps Dramatically Reduced
in Cooling Fan Assembly

Consistent quality at lower cost 72 secondary fasteners eliminated Dramatic reduction in fastening cycles - 24 down to 4 Reduced cycle time

Apr 2004

A six-fan assembly for a 19" rack server proved to be the ideal candidate for a dramatic reduction in fasteners and fastening cycles. As a result of Maysteel's redesign, what had been acknowledged as an assembly nightmare became a highly streamlined process.

The overall fan assembly contains a three-grill sub-assembly that forms one complete side, plus an interior assembly consisting of three individual fan grills. Because of the need for maximum open area, these six fan grills needed to be formed of wire rather than punched out of parent material. The problem then became attaching the grills efficiently. Whether on the three-grill assembly or individually, each fan grill requires four points of attachment. The original design called for these attachments to be made with two washers and a pop rivet per joint - a total of 48 washers and 24 rivets, all inserted by hand.

Maysteel's solution involved a pierce and extrude feature created automatically as the sheet metal is formed, then adding a clinching cycle to secure the fan grill. The triple-grill assembly is now secured in a single cycle, with one additional cycle each for the individual units. The result is now a total of four cycles to secure six fan grills, where 24 cycles had been required. In addition, fastener count is now zero, down from 72.

Original design (left) used three washers and a rivet to secure each of 24 joints. Maysteel's redesign (right) used pierce and extrude features, created during the regular forming process, and a clinching step.