This is the replacement Big Sert (oversize) insert that comes in the 3700BS universal headbolt kit

Time Sert inserts self locking. On installation the bottom internal threads of the insert are cold rolled to expand the mating external threads into the base material locking the insert in place.

Inserts are sold in 10 packs.

The post Big-Sert 37004 M11 x 2.0 x 30mm Head Bolt Insert appeared first on Thread Doctor.

 Insert Length Metric Is 30.0mm

 Professional Thread Repair

Time Sert Inserts Self Locking. On Installation The Bottom Internal Threads Of The Insert Are Cold Rolled To Expand The Mating External Threads Into The Base Material Locking The Insert In Place.

Inserts Are Sold In 10 Packs

The post Big-Sert 52125 M12 x 1.25 x 30.0mm Metric Steel Insert appeared first on Thread Doctor.

 Insert Length Metric Is 24.0mm

 Professional Thread Repair

Time Sert Inserts Self Locking. On Installation The Bottom Internal Threads Of The Insert Are Cold Rolled To Expand The Mating External Threads Into The Base Material Locking The Insert In Place.

Inserts Are Sold In 10 Packs.

The post Big-Sert 52123 M12 x 1.25 x 24.0mm Metric Steel Insert appeared first on Thread Doctor.

 Insert Length Metric Is 17.5mm

 Professional Thread Repair

Time Sert Inserts Self Locking. On Installation The Bottom Internal Threads Of The Insert Are Cold Rolled To Expand The Mating External Threads Into The Base Material Locking The Insert In Place.

Inserts Are Sold In 10 Packs.

The post Big-Sert 52122 M12 x 1.25 x 17.5mm Metric Steel Insert appeared first on Thread Doctor.

 Insert Length Metric Is 15.0mm

 Professional Thread Repair

Time Sert Inserts Self Locking. On Installation The Bottom Internal Threads Of The Insert Are Cold Rolled To Expand The Mating External Threads Into The Base Material Locking The Insert In Place.

Inserts Are Sold In 10 Packs.

The post Big-Sert 52121 M12 x 1.25 x 15.0mm Metric Steel Insert appeared first on Thread Doctor.

 Insert Length Metric Is 9.0mm

 Professional Thread Repair

Time Sert Inserts Self Locking. On Installation The Bottom Internal Threads Of The Insert Are Cold Rolled To Expand The Mating External Threads Into The Base Material Locking The Insert In Place.

Inserts Are Sold In 10 Packs

The post Big-Sert 52120 M12 x 1.25 x 9.0mm Metric Steel Insert appeared first on Thread Doctor.

 Insert Length Metric Is 30.0mm

 Professional Thread Repair

Time Sert Inserts Self Locking. On Installation The Bottom Internal Threads Of The Insert Are Cold Rolled To Expand The Mating External Threads Into The Base Material Locking The Insert In Place.

Inserts Are Sold In 10 Packs.

The post Big-Sert 52175 M12 x 1.75 x 30.0mm Metric Steel Insert appeared first on Thread Doctor.

 Insert Length Metric Is 24.0mm

 Professional Thread Repair

Time Sert Inserts Self Locking. On Installation The Bottom Internal Threads Of The Insert Are Cold Rolled To Expand The Mating External Threads Into The Base Material Locking The Insert In Place.

Inserts Are Sold In 10 Packs.

The post Big-Sert 52173 M12 x 1.75 x 24.0mm Metric Steel Insert appeared first on Thread Doctor.

 Insert Length Metric Is 16.2mm

 Professional Thread Repair

Time Sert Inserts Self Locking. On Installation The Bottom Internal Threads Of The Insert Are Cold Rolled To Expand The Mating External Threads Into The Base Material Locking The Insert In Place.

Inserts Are Sold In 10 Packs.

The post Big-Sert 52171 M12 x 1.75 x 16.2mm Metric Steel Insert appeared first on Thread Doctor.

 Insert Length Metric Is 12.0mm

 Professional Thread Repair

Time Sert Inserts Self Locking. On Installation The Bottom Internal Threads Of The Insert Are Cold Rolled To Expand The Mating External Threads Into The Base Material Locking The Insert In Place.

Inserts Are Sold In 10 Pack.

The post Big-Sert 52170 M12 x 1.75 x 12.0mm Metric Steel Insert appeared first on Thread Doctor.