Tapping

Calculations for Speed:

RPM = (3.82 x FPM) / diameter

FPM = (RPM x dia.) / 3.82

 

Tapping speeds shown are approximate and may vary for each application.  If you need additional information, please call our technical support at 1-866-583-TOOL.

 

Chart below shows Tapping Speed in FPM.

The numbers across the top (columns) are Threads Per Inch 

 

Material	7 or less	8-15	16-24	Over 24	Possible Surface Treatments
Zinc & Magnesium Alloys Wrought & Cast	65	77	88	100	04, 88, 89
Aluminum Alloys Wrought Cast	50 50	67 67	83 83	100 100	04, 88, 89 04, 88, 89, 90
Brass	50	60	70	80	02, 04, 82, 88
Cast Iron Gray, as cast	25	28	32	35	23, 84, 89
Copper	25	28	32	35	02, 04, 82, 88
Iron Ductile & Malleable	20	27	33	40	03, 23, 84, 88, 89, 90
Bronze	20	25	30	35	02, 04, 82, 88
Carbon Steel Low, Med. & Leaded Medium Carbon	20 20	30 23	40 27	50 30	03, 23, 84, 88, 89, 90 03, 23, 84, 88, 89, 90
Alloy Steel 4 - series	15	18	22	25	03, 23, 84, 88, 89, 90
Stainless Steel Free Machining 300 series, Cold Drawn Precipitation Hardening	20 15 8	27 18 12	33 22 16	40 25 20	03, 23, 84, 88, 89, 90 03, 23, 84, 88, 89, 90 03, 23, 84, 88, 89, 90
Titanium Alloys Under Rc30 Rc 30-40	15 5	18 8	22 12	25 15	04, 23, 82, 84, 90 04, 23, 82, 84, 90
Tool & Die Steel S, L, A, O & D Series	10	13	17	20	03, 23, 84, 88, 89, 90
High Temp Alloys Monel, Nickel Inconel	8 5	12 7	16 8	20 10	23, 82, 84, 88, 89, 90 23, 82, 84, 88, 89, 90

 

Surface Treatment Codes:

02 - Nitride

22 - Double Nitride

03 -Steam Oxide

23 - Nitride & Oxide

04 - Chrome Plate

88 - Titanium Nitride

89 - Titanium Carbonitride

84 - Titanium Aluminum Nitride

90 - Chromium Carbide

82 - Chromium Nitride