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BT Taper Retention Knobs with Coolant Hole
 |  |
Knob with Pilot |
Lock tool holders in place on CNC machines with a through-spindle coolant (TSC) system. They fit machines with a BT taper spindle. All meet industrial standards for tensile and shear strength. Also known as pull studs. These knobs have a pilot, which ensures precise alignment between the tool holder and spindle, reducing vibration and runout. To ensure compatibility with your machine, compare the features on these knobs, such as the location of O-ring seals and the pilot design, to those on your current knob. To upgrade a standard knob to one with a pilot, confirm that the pilot diameter is small enough to fit in your tool holder without touching the inner walls where the knob seats.
Use a torque wrench with a retention knob socket or a changeable-head torque wrench to tighten them.
Flange O-Ring Included—Knobs with flange O-rings block external coolant from entering your machine spindle. Match the O-ring placement and style to your current setup to ensure optimal sealing and performance.
Grip Angle—Grip angle is the sloped part of the knob that the machine grips to secure the tool holder. A 15˚ grip angle is sometimes referred to as a 75˚ grip angle. A 30˚ grip angle is sometimes referred to as a 60˚ grip angle.
Grip Angle | Projection | Head Dia. | Coolant Hole Diameter | Pilot Dia. | Collar Dia. | Head-to-Flange Lg. | Flange Thk. | Torque Range, ft·lbf | O-Rings Included | Mfr. | Mfr. Model No. | Mfr. Equiv. Model No. | Specs. Met | JIS Specification | Each | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
BT 30 Machine Taper | ||||||||||||||||||
M12 × 1.75 mm | ||||||||||||||||||
| 15° | 0.921" | 0.471" | 0.157" | 0.492" | 0.372" | 0.724" | 0.197" | 25 to 30 | — | T.J. Davies | PSC-344X15 | 30PMG, 326-21, 21144-C, HPS-B30-Kitamua-C, RS2M-0207-C | ISO 7388-3 | JIS B 6339 | 9487N11 | 000000 | ||
| 30° | 0.905" | 0.431" | 0.125" | 0.492" | 0.372" | 0.707" | 0.197" | 25 to 30 | — | T.J. Davies | PSC-585X60 | 3004TRKC, 21134-C, B30-6000H, HPS-17C, HPS-B30-MAS-60 C | ISO 7388-3 | JIS B 6339 | 9487N14 | 00000 | ||
| 45° | 0.905" | 0.431" | 0.125" | 0.492" | 0.372" | 0.707" | 0.197" | 25 to 30 | — | T.J. Davies | PSC-585X45 | 3003TRKC, 17817, B30-4500H, HPS-B30-MAS-45 C, P30T-2MGH, PS-130E, RB2M-0001-C | ISO 7388-3 | JIS B 6339 | 9487N13 | 00000 | ||
BT 40 Machine Taper | ||||||||||||||||||
M16 × 2 mm | ||||||||||||||||||
| 15° | 1.136" | 0.746" | 0.264" | 0.669" | 0.505" | 0.9" | 0.157" | 45 to 55 | — | T.J. Davies | PSC-480X15 | 711-22, 21130-C, 71122, DIN40ATRK, RS4M-0114-C | ISO 7388-3 | JIS B 6339 | 9487N16 | 00000 | ||
| 15° | 1.136" | 0.746" | 0.264" | 0.669" | 0.505" | 0.9" | 0.157" | 45 to 55 | Flange O-Ring, Head O-Ring in Coolant Hole | T.J. Davies | PSCO-480X15A | B40-1500 Mori EU, HPS-366E-1 | ISO 7388-3 | JIS B 6339 | 9487N15 | 00000 | ||
| 15° | 1.141" | 0.746" | 0.264" | 0.669" | 0.505" | 0.905" | 0.275" | 45 to 55 | — | T.J. Davies | PSC-444X15 | 40PH, 329-13, 21101-C, 32913, B40-1500 H, HPS-806-1, RS4M-0205-C | ISO 7388-3 | JIS B 6339 | 9487N17 | 00000 | ||
| 30° | 1.378" | 0.588" | 0.166" | 0.669" | 0.505" | 1.1" | 0.236" | 45 to 55 | — | T.J. Davies | PSC-444X60 | 311-13E, 4004TRKC, 17820, 31113E, B40-6000 H, HPS-2 C, RB4M-0002-C | — | JIS B 6339 | 9487N22 | 00000 | ||
| 45° | 0.752" | 0.74" | 0.264" | 0.669" | 0.505" | 0.552" | 0.120" | 45 to 55 | — | T.J. Davies | PSC-479 | 312-25, 21129-C, 31225, HPS-G51, MZ40TRKC, PS-G51 | ASME B5.50, ISO 7388-3 | JIS B 6339 | 9487N18 | 00000 | ||
| 45° | 0.752" | 0.74" | 0.264" | 0.669" | 0.505" | 0.552" | 0.236" | 45 to 55 | — | T.J. Davies | PSC-477 | 111-26A, 11126A, 21105-C, B40-FADAL C, F40TRKC, RS4M-0115-C | ASME B5.50, ISO 7388-3 | JIS B 6339 | 9487N19 | 00000 | ||
| 45° | 1.378" | 0.588" | 0.166" | 0.669" | 0.505" | 1.1" | 0.236" | 45 to 55 | — | T.J. Davies | PSC-444X45 | 311-13D, 4003TRKC, 17818, 31113D, B40-4500 H, HPS-1C, RB4M-0001-C | — | JIS B 6339 | 9487N21 | 00000 | ||
| 90° | 1.378" | 0.588" | 0.166" | 0.669" | 0.505" | 1.1" | 0.236" | 45 to 55 | — | T.J. Davies | PSC-444X90 | 311-13F, 4002TRKC, 17822, 31113F, B40-9000 H, HPS-08 C, RB4M-0003-C | — | JIS B 6339 | 9487N23 | 00000 | ||
BT 50 Machine Taper | ||||||||||||||||||
M24 × 3 mm | ||||||||||||||||||
| 30° | 1.77" | 0.906" | 0.276" | 0.984" | 0.787" | 1.378" | 0.394" | 85 to 110 | — | Lyndex Nikken | B50-6000(H)-EU | — | — | JIS B 6339 | 9487N26 | 00000 | ||
| 45° | 1.772" | 0.904" | 0.232" | 0.984" | 0.78" | 1.376" | 0.394" | 75 to 90 | Flange O-Ring, Head O-Ring in Coolant Hole | T.J. Davies | PSC-446X45 TOY | P50T-1H4 | — | JIS B 6339 | 9487N24 | 00000 | ||
| 45° | 1.772" | 0.904" | 0.309" | 0.984" | 0.78" | 1.376" | 0.394" | 75 to 90 | — | T.J. Davies | PSC-446X45 | 5003TRKC, 21140-C, 31643, B50-4500H, HPS-5 C, P50T-1H, RB6M-0001-C | — | JIS B 6339 | 9487N25 | 00000 | ||
BT Taper Retention Knobs
 |  |
Knob with Pilot |
Lock tool holders in place on CNC machines with a BT taper spindle. All meet industrial standards for tensile and shear strength. These knobs are also known as pull studs. They have a pilot, which ensures precise alignment between the tool holder and spindle, reducing vibration and runout. To ensure compatibility with your machine, compare the features on these knobs, such as the pilot design, to those on your current knob. If you want to upgrade a standard knob to one with a pilot, confirm that the pilot diameter is small enough to fit in your tool holder without touching the inner walls where the knob seats.
Use a torque wrench with a retention knob socket or a changeable-head torque wrench to tighten them.
Grip Angle—Grip angle is the sloped part of the knob that the machine grips to secure the tool holder. A 15˚ grip angle is sometimes referred to as a 75˚ grip angle. A 30˚ grip angle is sometimes referred to as a 60˚ grip angle.
Grip Angle | Projection | Head Dia. | Pilot Dia. | Collar Dia. | Head-to-Flange Lg. | Flange Thk. | Torque Range, ft·lbf | Mfr. | Mfr. Model No. | Mfr. Equiv. Model No. | Specs. Met | JIS Specification | Each | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
BT 30 Machine Taper | ||||||||||||||||
M12 × 1.75 mm | ||||||||||||||||
| 15° | 0.921" | 0.471" | 0.492" | 0.372" | 0.724" | 0.197" | 25 to 30 | T.J. Davies | PS-344X15 | 21144, HPS-B30-Kitamua, PS-801, RS2M-0207 | ISO 7388-3 | JIS B 6339 | 9485N11 | 000000 | ||
| 15° | 0.921" | 0.51" | 0.492" | 0.372" | 0.724" | 0.126" | 25 to 30 | T.J. Davies | PSR-370X15 | 30PMGH, 750-19, 75019, 75019/49019 | ISO 7388-3 | JIS B 6339 | 9485N12 | 00000 | ||
| 30° | 0.905" | 0.431" | 0.492" | 0.372" | 0.707" | 0.197" | 25 to 30 | T.J. Davies | PS-585X60 | 311-09A, 3004TRK, 17806, B30-6000, HPS-17, HPS-B30-MAS-60, PS-17, RB2M-0002 | ISO 7388-3 | JIS B 6339 | 9485N15 | 00000 | ||
| 45° | 0.905" | 0.431" | 0.492" | 0.372" | 0.707" | 0.197" | 25 to 30 | T.J. Davies | PS-585X45 | 311-09, 3003TRK, 17801, 31109, B30-4500, HPS-16, HPS-B30-MAS-45, P30T-2MG, PS-16, RB2M-0001 | ISO 7388-3 | JIS B 6339 | 9485N14 | 00000 | ||
| 90° | 0.905" | 0.431" | 0.492" | 0.372" | 0.707" | 0.197" | 25 to 30 | T.J. Davies | PS-585X90 | 311-09B, 17812, 31109B, B30-9000, P35T-1 | ISO 7388-3 | JIS B 6339 | 9485N16 | 00000 | ||
BT 40 Machine Taper | ||||||||||||||||
M16 × 2 mm | ||||||||||||||||
| 15° | 1.141" | 0.746" | 0.669" | 0.505" | 0.905" | 0.275" | 45 to 55 | T.J. Davies | PS-444X15 | 40PH, 329-12, 4020NTRK, 21101, 32912, B40-1500, HPS-805, PS-805, RS4M-0205 | — | JIS B 6339 | 9485N17 | 00000 | ||
| 30° | 1.378" | 0.588" | 0.669" | 0.505" | 1.1" | 0.236" | 45 to 55 | T.J. Davies | PS-444X60 | 311-13A, 4004TRK, 17808, 31113A, B40-6000, HPS-2, RB4M-0002 | — | JIS B 6339 | 9485N22 | 00000 | ||
| 45° | 0.752" | 0.74" | 0.669" | 0.505" | 0.552" | 0.236" | 45 to 55 | T.J. Davies | PS-477 | 111-26, 11126, 21105, B40-FADAL, F40TRK, RS4M-0115 | ASME B5.50, ISO 7388-3 | JIS B 6339 | 9485N18 | 00000 | ||
| 45° | 1.378" | 0.588" | 0.669" | 0.505" | 1.1" | 0.236" | 45 to 55 | T.J. Davies | PS-444X45 | 311-13, 4003TRK, 17803, 31113, B50-4500, HPS-1, P40T-1, PS-70, RB4M-0001 | — | JIS B 6339 | 9485N19 | 00000 | ||
| 45° | 1.546" | 0.592" | 0.669" | 0.505" | 1.25" | 0.187" | 45 to 55 | T.J. Davies | PS-554 | 171-26, 17126, 21116 | ASME B5.50, ISO 7388-3 | JIS B 6339 | 9485N21 | 00000 | ||
| 90° | 1.378" | 0.588" | 0.669" | 0.505" | 1.1" | 0.236" | 45 to 55 | T.J. Davies | PS-444X90 | 311-13B, 4002TRK, 17814, 31113B, B40-9000, HPS-08, POM40F, POM40MG, RB4M-0003 | — | JIS B 6339 | 9485N23 | 00000 | ||
BT 50 Machine Taper | ||||||||||||||||
M24 × 3 mm | ||||||||||||||||
| 45° | 1.772" | 0.904" | 0.984" | 0.78" | 1.376" | 0.394" | 75 to 95 | T.J. Davies | PS-446X45 | 311-17, 5003TRK, 21140, 31117, B50-4500, HPS-5, RB6M-0001 | — | JIS B 6339 | 9485N24 | 00000 | ||
| 90° | 1.772" | 0.904" | 0.984" | 0.78" | 1.376" | 0.394" | 75 to 95 | T.J. Davies | PS-446X90 | 311-17B, 5002TRK, 21139, 31117B, B50-9000, RB6M-0003 | — | JIS B 6339 | 9485N25 | 00000 | ||
