Spearhead High Speed Steel 45 Degree Bearing Bur Kit of 24 Pieces

Important Notice: 10/22/26: Spearhead has stopped production.  The factory is closed and the company is out of business.  We have limited stock remaining.  Please see our listing for individual HSS 45 Degree Bearing Burs for remaining availability.

A 45-degree bearing bur, also called a hart bur, cuts the angled seat that holds a stone in place during setting work.

Spearhead High Speed Steel 45-degree bearing burs are hand cut by expert craftsmen in the USA, delivering the precision and longevity that quality jewelers demand. Each bur in this kit is sized and stamped directly on the 3/32" shank, a hallmark of the Spearhead line that makes identification fast and reliable at the bench.

High Speed Steel outperforms imported Tungsten Vanadium Carbon Steel burs in hardness and edge retention. Because these burs are hand cut rather than machine cut, they hold a sharper edge longer, reducing the frequency of replacement and delivering cleaner, more consistent seats. HSS 45-degree bearing burs are the preferred choice of quality jewelers for stone setting work.

This kit assembles the first 24 sizes in the Spearhead HSS 45-degree bearing bur line, spanning No. 2 (1.1mm) through No. 30 (8.0mm), a comprehensive range suited to everyday setting needs. The burs arrive in a 36-hole wood bur box sized for 3/32" shanks, measuring 5" wide by 3" deep by 2-5/8" high. No. 34 (11.1mm) is not included in this set and is available separately as Otto Frei part #119.414.

The following numbers are not manufactured in the HSS 45-degree bearing bur line and are therefore not present in any set: No. 1, 21, 23, 25, 27, 29, 31, and 33.

Features

• Hand cut by expert craftsmen in the USA
• High Speed Steel construction for superior hardness and edge retention
• Longer service life compared to Tungsten Vanadium Carbon Steel burs
• Size stamped on each 3/32" shank for quick bench identification
• 45-degree bearing angle suited to stone setting applications
• Kit spans No. 2 (1.1mm) – No. 30 (8.0mm), covering 24 sizes
• Supplied in a 36-hole wood bur box for 3/32" shanks

Notes

• Kit may ship incomplete due to supply constraints; Otto Frei will confirm available sizes and adjust pricing accordingly.
• No. 34 (11.1mm) is not included in this kit; it is available separately as Otto Frei part #119.414.
• Numbers 1, 21, 23, 25, 27, 29, 31, and 33 are not produced in the HSS 45-degree bearing bur line.