Round Serrated Spigot Rivet Bush Installation


The round pattern bush features a serrated spigot providing a durable and effective alternative to the Hexagon pattern. When installed, the serrations provide discreet anchorage against Torsional resistance and pull out loads.

The round pattern is designed to be riveted or ‘peened’ over the sheet metal to provide a strong and re-usable thread assembly.




Serrated Spigot Rivet Bush Installation Step 1 Serrated Spigot Rivet Bush Installation Step 2 Serrated Spigot Rivet Bush Installation Step 3
Ensure the correct spigot length has been selected for sheet thickness being used.  Select the appropriate hole size from the table below for the bush required. Punch the hole diameter into the sheet material. Place the sheet metal on the bush so the spigot protrudes through the hole. If the bush is not seated ‘square’ in the hole, the joint will be imperfect and mating threads will mis-align. Using a profiled punch, apply only sufficient pressure to ‘peen’ the spigot over into the sheet metal and allow the serrations on the spigot to embed in the face of the sheet, providing torsional resistance. After installation the spigot is to be flush. 


Serrated Spigot Rivet Bush Installation Step 5 Rivet Bush in Sheet metal For best torsional and pull-out resistance, the serrated spigot should be embedded in the face of the sheet material and the spigot should be flush with the underside of the sheet after installation.

Hole Sizes - Metric (mm)

Thread form M2.5 M3 M3.5 M4 M5 M6 M8 M10 M12
Recommended hole size +0.05 -0.00mm 5.54 5.54 6.73 6.73 7.92 9.52 12.70 15.87 19.05

Hole Sizes - Inch (inches)

Thread Form BSW/F - 1/8" - 5/32" 3/16" 1/4" 5/16" 3/8" 1/2"
BA 8 6.5 4 3 2 - - - -
UNC 2 4 6 8 10 1/4" 5/16" 3/8" 1/2"
UNF 2 4 6 8 10 1/4" 5/16" 3/8" 1/2"
Recommended hole size +0.002 -0.000" .218 .218 .265 .265 .312 .375 .500 .625 .750



Standard Rivet Bush Punch

Detail 1 - Oil hardening steel 665 M17 (EN34) 

Note: 760°C - 780°C Oil quench Temper 150°C - 200°C

Punch Dimensions 
Thread Size A B
M2.5/M3 9.05 4.39
M3.5/M4 10.50 5.49
M5 12.00 6.65
M6 14.00 8.23
M8 16.30 11.05
M10 21.90 14.12
M12 25.40 16.61
Note: Due to the fact that fastening applications differ greatly, the above information is for guidance only and is correct to the best of our knowledge. The customer must satisfy themselves with the performance of the fastener and validity of the data. TR Fastenings will not be held responsible for any failure that may occur from the use of this information.