GY NMT Nut Screwing Taps

BSW & BSF , Coarse Pitch
As per IS: 6175 Part 5 & DIN 357

Nut Screwing Taps, manufactured in accordance with IS: 6175, are specialized cutting tools designed specifically for the high-production threading of nuts. Unlike standard hand taps, these are engineered to handle the unique stresses of continuous nut tapping, ensuring concentricity and thread accuracy across large batches.

Key Features

  • Extended Lead Chamfer: These taps typically feature a very long lead (chamfer) length, often covering 10 to 15 threads. This distributes the cutting load over many teeth, reducing wear and allowing for smoother entry into the nut blank.
  • Longer Shank: The shank is significantly longer than standard taps. This design allows multiple tapped nuts to collect on the shank during a single operation before they are cleared, making them ideal for use on automatic nut-tapping machines.
  • Material and Hardness: Manufactured from premium High-Speed Steel (HSS), these tools are heat-treated to maintain a high red-hardness, ensuring the cutting edges remain sharp even under the thermal stress of high-speed manufacturing.
  • Thread Profile: Designed for ISO Metric Coarse Threads, ensuring full compatibility with international fastening standards.
TECHNICAL SPECIFICATION FOR COARSE PITCH
Designation d nominal Approximate pitch d1 h9 l L Square a h11 Square l2
1/4 – 20-BSW 6.350 1.2700 4,50 32 110 3.55 6
5/16 – 18-BSW 7.938 1.411 6,30 40 125 5 8
3/8 – 16-BSW 9.525 1.588 8 45 140 6.3 9
7/16 – 14 – BSW 11,112 1,814 8,0 45 160 6.3 9
1/2 – 12-BSW 12,700 2.117 9,0 50 180 7.1 10
9/16 – 12-BSW 14,288 2,117 11,2 66 200 9 12
5/8 – 11-BSW 15,875 2,309 12,5 63 200 10 13
3/4 – 10-BSW 19,050 2,540 14,0 70 250 11.2 14
7/8 – 9-BSW 22,225 2,822 16,0 80 280 12.5 16
TECHNICAL SPECIFICATION FOR COARSE PITCH
Designation d nominal Approximate pitch d1 h9 l L Square a h11 Square l2
7/16 – 18 – BSF11,1121.4148,025,085,06,39
1/2 – 16 – BSF12,7001.5889,029,089,07,110
9/16 – 16 – BSF14,2881.58811,230,095,09,012
5/8 – 14 – BSF15,8751.81412,532,0102,010,013
11/16 – 14 – BSF17,4631.81412,537,0112,011,214.0
3/4 – 12 – BSF19,0501.81412,537,0112,011,214.0
7/8 – 11 – BSF22,2252.30916,038,0118,012,516
1 – 10 – BSF25,4002.54018,045,0130,014,018
1 1/8 – 9 – BSF28,5752.82220,037,0127,016,020.0
1 1/4 – 9 – BSF31,7502.82222,437,0137,018,022.0
1 3/8 – 8 – BSF34,9253.17525,039,0144,020,024.0
1 1/2 – 8 – BSF38,1003.17528,039,0149,022,426.0
1 5/8 – 8 – BSF38,1003.17528,039,0149,022,426.0
1 3/4 – 7 – BSF44,4503.62931,545,0165,025,028.0
2 – 7 – BSF50,8003.62935,545,0175,028,031.0
2 1/4 – 6 – BSF57,1504.23340,048,0193,031,534.0
2 1/2 – 6 – BSF63,5004.23340,048,0193,031,534.0
2 3/4 – 6 – BSF69,8504.23345,048,0203,035,538.0
3 – 5 – BSF76,2005.08050,051,0226,040,042.0
3 1/4 – 5 – BSF82,5505.08050,051,0226,040,042.0
3 1/2 – 4.1/2 – BSF88,9005.64450,051,0226,040,042.0