TIP: Broken Carbide twist drills can be used to make carbide gravers and carbide scribers

Most horologists find the easiest way to use these micro drill bits is by first finding the centre with a graver and then holding a micro drill in a pin-vice and then taking them to the work. Use very light pressure whilst taking the drill in and out periodically. No lubrication is necessary, although a small dab of oil can help. 

Extra care is needed with handling these drills as they are very delicate, especially sizes from 0.1mm - 0.4mm. Make sure everything is running true without any lateral movement.

A solid carbide twist drill is perfect for delicate drilling through hard materials for model engineering, archaeology and scientific laboratory work.

Ideal for drilling through PCB, and printed circuit boards. Made of fibreglass, printed circuit boards require a tough micro drill, and our tungsten carbide drills range will outperform similar HSS drill bits.

Look at the different drill bit sizes of carbide micro drills to determine their effective cutting length, spindle speed, feed rate and chip load.

Size (mm)			Effective cutting length (mm)	Spindle speed (rpm)	Feed rate (m/mm)	Chip load (mm/rev)
0.1			1.5	125,000	0.8	0.006
0.2			3.5	125,000	1.5	0.012
0.3			5.5	125,000	2.3	0.018
0.4			7.0	125,000	2.9	0.024
0.5			8.5	95,500	2.9	0.03
0.6			9.5	79,600	2.9	0.036
0.7			9.5	68,200	2.9	0.042
0.8			9.5	59.700	2.9	0.048
0.9			9.5	53,100	2.9	0.054
1.0			10.5	47,800	2.9	0.06
1.1			10.5	43,400	2.9	0.066
1.2			10.5	39,800	2.9	0.072
1.3			12.0	36,700	2.9	0.078
1.4			12.0	24,100	2.9	0.084
1.5			12.0	31,800	2.9	0.090
1.6			12.0	29,900	2.9	0.096
1.7			12.0	28,100	2.8	0.10
1.8			12.0	26,500	2.7	0.10
1.9			12.0	25,100	2.5	0.10
2.0			12.0	23,900	2.4	0.10
2.1			12.0	22,700	2.3	0.10
2.2			12.0	21,700	2.2	0.10
2.3			12.0	20,800	2.1	0.10
2.4			12.0	20,000	2.0	0.10
2.5			12.0	20,000	2.0	0.10
2.6			12.0	20,000	2.0	0.10
2.7			12.0	20,000	2.0	0.10
2.8			12.0	20,000	2.0	0.10
2.9			12.0	20,000	2.0	0.10
3.0			12.0	20,000	2.0	0.10