KATO CoilThread STI Taps

KATO CoilThread STI Taps

Dependable High Speed Steel Taps for Screw Thread Inserts.

KATO CoilThread STI (Screw Thread Inserts) Taps are designed specifically to create internal threads that will accommodate a KATO CoilThread insert. CoilThread Taps can be used in a range of materials including aluminum, magnesium, steel, plastics and other free machining materials. KATO CoilThread Taps are manufactured from High Speed Steel for durability and prolonged tooling life.

KATO offers four STI tap styles for various applications:

Plug Style

Plug Style 4-Thread Chamfer

(4-Thread Chamfer)

Easy starting for through-holes and blind holes.


Bottoming Style

Bottoming Style 2-Thread Chamfer

(2-Thread Chamfer)

Ideal for blind holes that are drilled to a minimum depth.


Spiral Pointed Plug

Spiral Pointed Plug 4-Thread Chamfer

(4-Thread Chamfer)

Free-cutting for use in long through-holes and in blind holes with chip clearance.


Spiral Flute Bottoming

Spiral Flute Bottoming 2-Thread Chamfer

(2-Thread Chamfer)

Designed to pull chips out of deep or blind holes in soft materials


Features & Benefits

  • KATO STI Taps can be used for both Tangless and Tanged CoilThread inserts.
  • Available in 3B and 2B (Unified) or 4H and 5H (Metric) Class of Fit.
  • Available for a full range of Unified and Metric thread sizes.
  • Compatiable with screw thread inserts from Heli-Coil ®, Recoil and others.
  • Lower cost than similar taps from competitors.

Part Numbers


For fast and accurate part numbers and technical information on specific inserts try out the KATO Product Wizard.

Example of a KATO STI Taps part number:


CT C - 02 SRP - H1

1  2     3    4      5


1
Tool Type
2
Thread Designation
3
Size Designation
4
Style / Type
5
Class of Fit
CT - CoilThread Tap (STI) C - Unified Coarse
F - Unified Fine
M - Metric
See Chart Below SRP - Standard Regular Plug
SRB - Standard Regular Bottoming
SPP - Spiral Point Plug
SFB - Spiral Flute Bottoming
See Notes Below
Thread
Size
Standard Regular Finishing Spiral Pointed Spiral Flute
Plug Bottoming Plug Bottoming
3B 2B 3B 2B 3B 2B 3B 2B
Unified Coarse
2-56CTC-02SRP-H1CTC-02SRP-H2CTC-02SRB-H1CTC-02SRB-H2CTC-02SPP-H1CTC-02SPP-H2CTC-02SFB-H1CTC-02SFB-H2
3-48CTC-03SRP-H1CTC-03SRP-H2CTC-03SRB-H1CTC-03SRB-H2CTC-03SPP-H1CTC-03SPP-H2CTC-03SFB-H1CTC-03SFB-H2
4-40CTC-04SRP-H1CTC-04SRP-H2CTC-04SRB-H1CTC-04SRB-H2CTC-04SPP-H1CTC-04SPP-H2CTC-04SFB-H1CTC-04SFB-H2
5-40CTC-05SRP-H1CTC-05SRP-H2CTC-05SRB-H1CTC-05SRB-H2CTC-05SPP-H1CTC-05SPP-H2CTC-05SFB-H1CTC-05SFB-H2
6-32CTC-06SRP-H2CTC-06SRP-H3CTC-06SRB-H2CTC-06SRB-H3CTC-06SPP-H2CTC-06SPP-H3CTC-06SFB-H2CTC-06SFB-H3
8-32CTC-2SRP-H2CTC-2SRP-H3CTC-2SRB-H2CTC-2SRB-H3CTC-2SPP-H2CTC-2SPP-H3CTC-2SFB-H2CTC-2SFB-H3
10-24CTC-3SRP-H2CTC-3SRP-H3CTC-3SRB-H2CTC-3SRB-H3CTC-3SPP-H2CTC-3SPP-H3CTC-3SFB-H2CTC-3SFB-H3
12-24CTC-1SRP-H2CTC-1SRP-H3CTC-1SRB-H2CTC-1SRB-H3CTC-1SPP-H2CTC-1SPP-H3CTC-1SFB-H2CTC-1SFB-H3
1/4-20CTC-4SRP-H2CTC-4SRP-H3CTC-4SRB-H2CTC-4SRB-H3CTC-4SPP-H2CTC-4SPP-H3CTC-4SFB-H2CTC-4SFB-H3
5/16-18CTC-5SRP-H3CTC-5SRP-H4CTC-5SRB-H3CTC-5SRB-H4CTC-5SPP-H3CTC-5SPP-H4CTC-5SFB-H3CTC-5SFB-H4
3/8-16CTC-6SRP-H3CTC-6SRP-H4CTC-6SRB-H3CTC-6SRB-H4CTC-6SPP-H3CTC-6SPP-H4CTC-6SFB-H3CTC-6SFB-H4
7/16-14CTC-7SRP-H3CTC-7SRP-H4CTC-7SRB-H3CTC-7SRB-H4CTC-7SPP-H3CTC-7SPP-H4CTC-7SFB-H3CTC-7SFB-H4
1/2-13CTC-8SRP-H3CTC-8SRP-H4CTC-8SRB-H3CTC-8SRB-H4CTC-8SPP-H3CTC-8SPP-H4CTC-8SFB-H3CTC-8SFB-H4
9/16-12CTC-9SRP-H3CTC-9SRP-H4CTC-9SRB-H3CTC-9SRB-H4------------
5/8-11CTC-10SRP-H3CTC-10SRP-H4CTC-10SRB-H3CTC-10SRB-H4------------
3/4-10CTC-12SRP-H3CTC-12SRP-H5CTC-12SRB-H3CTC-12SRB-H5------------
7/8-9CTC-14SRP-H3CTC-14SRP-H5CTC-14SRB-H3CTC-14SRB-H5------------
1-8CTC-16SRP-H4CTC-16SRP-H6CTC-16SRB-H4CTC-16SRB-H6------------
Unified Fine
0-80CTF-00SRP-H1CTF-00SRP-H2CTF-00SRB-H1CTF-00SRB-H2------------
3-56CTF-03SRP-H1CTF-03SRP-H2CTF-03SRB-H1CTF-03SRB-H2CTF-03SPP-H1CTF-03SPP-H2CTF-03SFB-H1CTF-03SFB-H2
4-48CTF-04SRP-H1CTF-04SRP-H2CTF-04SRB-H1CTF-04SRB-H2CTF-04SPP-H1CTF-04SPP-H2CTF-04SFB-H1CTF-04SFB-H2
6-40CTF-06SRP-H1CTF-06SRP-H2CTF-06SRB-H1CTF-06SRB-H2CTF-06SPP-H1CTF-06SPP-H2CTF-06SFB-H1CTF-06SFB-H2
8-36CTF-2SRP-H1CTF-2SRP-H2CTF-2SRB-H1CTF-2SRB-H2CTF-2SPP-H1CTF-2SPP-H2CTF-2SFB-H1CTF-2SFB-H2
10-32CTF-3SRP-H2CTF-3SRP-H3CTF-3SRB-H2CTF-3SRB-H3CTF-3SPP-H2CTF-3SPP-H3CTF-3SFB-H2 CTF-3SFB-H3
1/4-28CTF-4SRP-H2CTF-4SRP-H3CTF-4SRB-H2CTF-4SRB-H3CTF-4SPP-H2CTF-4SPP-H3CTF-4SFB-H2CTF-4SFB-H3
5/16-24CTF-5SRP-H2CTF-5SRP-H3CTF-5SRB-H2CTF-5SRB-H3CTF-5SPP-H2CTF-5SPP-H3CTF-5SFB-H2CTF-5SFB-H3
3/8-24CTF-6SRP-H2CTF-6SRP-H3CTF-6SRB-H2CTF-6SRB-H3CTF-6SPP-H2CTF-6SPP-H3CTF-6SFB-H2CTF-6SFB-H3
7/16-20CTF-7SRP-H3CTF-7SRP-H4CTF-7SRB-H3CTF-7SRB-H4CTF-7SPP-H3CTF-7SPP-H4CTF-7SFB-H3CTF-7SFB-H4
1/2-20CTF-8SRP-H3CTF-8SRP-H4CTF-8SRB-H3CTF-8SRB-H4CTF-8SPP-H3CTF-8SPP-H4CTF-8SFB-H3CTF-8SFB-H4
9/16-18CTF-9SRP-H3CTF-9SRP-H4CTF-9SRB-H3CTF-9SRB-H4------------
5/8-18CTF-10SRP-H3CTF-10SRP-H4CTF-10SRB-H3CTF-10SRB-H4------------
3/4-16CTF-12SRP-H3CTF-12SRP-H4CTF-12SRB-H3CTF-12SRB-H4------------
7/8-14CTF-14SRP-H3CTF-14SRP-H4CTF-14SRB-H3CTF-14SRB-H4------------
1-12CTF-16SRP-H4CTF-16SRP-H6CTF-16SRB-H4CTF-16SRB-H6------------


Thread
Size
Standard Regular Finishing
Plug Bottoming
4H 5H 4H 5H
Metric Coarse
M2.X4CTM-2X.4SRP-4HCTM-2X.4SRP-5HCTM-2X.4SRB-4HCTM-2X.4SRB-5H
M2.2X.45CTM-2.2X.45SRP-4HCTM-2.2X.45SRP-5HCTM-2.2X.45SRB-4HCTM-2.2X.45SRB-5H
M2.5X.45CTM-2.5X.45SRP-4HCTM-2.5X.45SRP-5HCTM-2.5X.45SRB-4HCTM-2.5X.45SRB-5H
M3X.5CTM-3X.5SRP-4HCTM-3X.5SRP-5HCTM-3X.5SRB-4HCTM-3X.5SRB-5H
M3.5X.6CTM-3.5X.6SRP-4HCTM-3.5X.6SRP-5HCTM-3.5X.6SRB-4HCTM-3.5X.6SRB-5H
M4X.7CTM-4X.7SRP-4HCTM-4X.7SRP-5HCTM-4X.7SRB-4HCTM-4X.7SRB-5H
M5X.8CTM-5X.8SRP-4HCTM-5X.8SRP-5HCTM-5X.8SRB-4HCTM-5X.8SRB-5H
M6X1CTM-6X1SRP-4HCTM-6X1SRP-5HCTM-6X1SRB-4HCTM-6X1SRB-5H
M7X1CTM-7X1SRP-4HCTM-7X1SRP-5HCTM-7X1SRB-4HCTM-7X1SRB-5H
M8X1.25CTM-8X1.25SRP-4HCTM-8X1.25SRP-5HCTM-8X1.25SRB-4HCTM-8X1.25SRB-5H
M10X1.5CTM-10X1.5SRP-4HCTM-10X1.5SRP-5HCTM-10X1.5SRB-4HCTM-10X1.5SRB-5H
M12X1.75CTM-12X1.75SRP-4HCTM-12X1.75SRP-5HCTM-12X1.75SRB-4HCTM-12X1.75SRB-5H
M14X2CTM-14X2SRP-4HCTM-14X2SRP-5HCTM-14X2SRB-4HCTM-14X2SRB-5H
M16X2CTM-16X2SRP-4HCTM-16X2SRP-5HCTM-16X2SRB-4HCTM-16X2SRB-5H
M18X2.5CTM-18X2.5SRP-4HCTM-18X2.5SRP-5HCTM-18X2.5SRB-4HCTM-18X2.5SRB-5H
M20X2.5CTM-20X2.5SRP-4HCTM-20X2.5SRP-5HCTM-20X2.5SRB-4HCTM-20X2.5SRB-5H
M22X2.5CTM-22X2.5SRP-4HCTM-22X2.5SRP-5HCTM-22X2.5SRB-4HCTM-22X2.5SRB-5H
M24X3CTM-24X3SRP-4HCTM-24X3SRP-5HCTM-24X3SRB-4HCTM-24X3SRB-5H
Metric Fine
M8X1CTM-8X1SRP-4HCTM-8X1SRP-5HCTM-8X1SRB-4HCTM-8X1SRB-5H
M10X1CTM-10X1SRP-4HCTM-10X1SRP-5HCTM-10X1SRB-4HCTM-10X1SRB-5H
M10X1.25CTM-10X1.25SRP-4HCTM-10X1.25SRP-5HCTM-10X1.25SRB-4HCTM-10X1.25SRB-5H
M12X1.25CTM-12X1.25SRP-4HCTM-12X1.25SRP-5HCTM-12X1.25SRB-4HCTM-12X1.25SRB-5H
M12X1.5CTM-12X1.5SRP-4HCTM-12X1.5SRP-5HCTM-12X1.5SRB-4HCTM-12X1.5SRB-5H
M14X1.5CTM-14X1.5SRP-4HCTM-14X1.5SRP-5HCTM-14X1.5SRB-4HCTM-14X1.5SRB-5H
M16X1.5CTM-16X1.5SRP-4HCTM-16X1.5SRP-5HCTM-16X1.5SRB-4HCTM-16X1.5SRB-5H
M18X1.5CTM-18X1.5SRP-4HCTM-18X1.5SRP-5HCTM-18X1.5SRB-4HCTM-18X1.5SRB-5H
M20X1.5CTM-20X1.5SRP-4HCTM-20X1.5SRP-5HCTM-20X1.5SRB-4HCTM-20X1.5SRB-5H
M22X1.5CTM-22X1.5SRP-4HCTM-22X1.5SRP-5HCTM-22X1.5SRB-4HCTM-22X1.5SRB-5H
M18X2CTM-18X2SRP-4HCTM-18X2SRP-5HCTM-18X2SRB-4HCTM-18X2SRB-5H
M20X2CTM-20X2SRP-4HCTM-20X2SRP-5HCTM-20X2SRB-4HCTM-20X2SRB-5H
M22X2CTM-22X2SRP-4HCTM-22X2SRP-5HCTM-22X2SRB-4HCTM-22X2SRB-5H
M24X2CTM-24X2SRP-4HCTM-24X2SRP-5HCTM-24X2SRB-4HCTM-24X2SRB-5H


Thread
Size
Spiral Pointed Spiral Flute
Plug Bottoming
4H 5H 4H 5H
Metric Coarse
M2.X4CTM-2XSPP-4HCTM-2X.4SPP-5HCTM-2X.4SFB-4HCTM-2X.4SFB-5H
M2.2X.45CTM-2.2X.45SPP-4HCTM-2.2X.45SPP-5HCTM-2.2X.45SFB-4HCTM-2.2X.45SFB-5H
M2.5X.45CTM-2.5X.45SPP-4HCTM-2.5X.45SPP-5HCTM-2.5X.45SFB-4HCTM-2.5X.45SFB-5H
M3X.5CTM-3X.5SPP-4HCTM-3X.5SPP-5HCTM-3X.5SFB-4HCTM-3X.5SFB-5H
M3.5X.6CTM-3.5X.6SPP-4HCTM-3.5X.6SPP-5HCTM-3.5X.6SFB-4HCTM-3.5X.6SFB-5H
M4X.7CTM-4X.7SPP-4HCTM-4X.7SPP-5HCTM-4X.7SFB-4HCTM-4X.7SFB-5H
M5X.8CTM-5X.8SPP-4HCTM-5X.8SPP-5HCTM-5X.8SFB-4HCTM-5X.8SFB-5H
M6X1CTM-6X1SPP-4HCTM-6X1SPP-5HCTM-6X1SFB-4HCTM-6X1SFB-5H
M7X1CTM-7X1SPP-4HCTM-7X1SPP-5HCTM-7X1SFB-4HCTM-7X1SFB-5H
M8X1.25CTM-8X1.25SPP-4HCTM-8X1.25SPP-5HCTM-8X1.25SFB-4HCTM-8X1.25SFB-5H
M10X1.5CTM-10X1.5SPP-4HCTM-10X1.5SPP-5HCTM-10X1.5SFB-4HCTM-10X1.5SFB-5H
M12X1.75CTM-12X1.75SPP-4HCTM-12X1.75SPP-5HCTM-12X1.75SFB-4HCTM-12X1.75SFB-5H
M14X2------------
M16X2------------
M18X2.5------------
M20X2.5------------
M22X2.5------------
M24X3------------
Metric Fine
M8X1CTM-8X1SPP-4HCTM-8X1SPP-5HCTM-8X1SFB-4HCTM-8X1SFB-5H
M10X1CTM-10X1SPP-4HCTM-10X1SPP-5HCTM-10X1SFB-4HCTM-10X1SFB-5H
M10X1.25CTM-10X1.25SPP-4HCTM-10X1.25SPP-5HCTM-10X1.25SFB-4HCTM-10X1.25SFB-5H
M12X1.25CTM-12X1.25SPP-4HCTM-12X1.25SPP-5HCTM-12X1.25SFB-4HCTM-12X1.25SFB-5H
M12X1.5CTM-12X1.5SPP-4HCTM-12X1.5SPP-5HCTM-12X1.5SFB-4HCTM-12X1.5SFB-5H
M14X1.5------------
M16X1.5------------
M18X1.5------------
M20X1.5------------
M22X1.5------------
M18X2------------
M20X2------------
M22X2------------
M24X2------------

Please Note:

  • The "H" limit number (last digit in part numbers above) indicates the number of .0005 inch increments the tap's maximum pitch diameter is above the basic (minimum).
  • The Class of Fit specifies the pitch diameter tolerance of the tapped hole, with class 3B (Unified) and 4H (Metric) being the tighter range usually specified in military/aerospace applications. Class 2B (Unified) and 5H (Metric) taps provide a broader tolerance range or looser fit, and are normally specified in commerical/industrial applications.
  • The Class of Fit of the installed insert is controlled by the Class of Fit of the tapped hole.

Specifications

All dimensions for unified size (in.)| All dimensions for metric size (mm.) | All dimensions are are for reference only.

Plug Style

Plug Style 4-Thread Chamfer Plug Style 4-Thread Chamfer

Bottoming Style

Bottoming Style 2-Thread Chamfer Bottoming Style 2-Thread Chamfer

Spiral Pointed Plug

Spiral Pointed Plug 4-Thread Chamfer Spiral Pointed Plug 4-Thread Chamfer

Spiral Flute Bottoming

Spiral Flute Bottoming 2-Thread Chamfer Spiral Flute Bottoming 2-Thread Chamfer

Thread
Size
Tap Dimensions Number of Flutes
Length
Overall
A
Length
of Thread
B
Length
of Square
C
Diameter
of Shank
D
Size of
Square
Finishing
Plug &
Bottoming
Spiral
Point
Plug
Spiral
Flute
Bottoming
Unified Coarse
2-561.880.560.190.140.11322
3-481.940.630.190.140.11322
4-402.000.690.190.140.11322
5-402.130.750.250.170.13323
6-322.380.880.250.190.15323
8-322.380.940.280.220.17323
10-242.501.000.310.260.19323
12-242.721.130.380.320.24323
1/4-202.721.130.380.320.24323
5/16-182.941.250.440.380.29433
3/8-163.381.660.440.370.28433
7/16-143.591.660.500.430.32434
1/2-133.811.810.560.480.36434
9/16-124.031.810.630.540.414----
5/8-114.252.000.690.590.444----
3/4-104.692.220.750.700.524----
7/8-95.132.500.810.800.604----
1-85.752.561.001.020.774----
1-1/8-76.063.001.171.110.834----
1-1/4-76.383.001.131.230.934----
1-3/8-66.693.191.131.310.984----
1-1/2-67.003.191.251.431.076----
Unified Fine
0-801.700.380.230.140.113------
3-561.940.630.190.140.11322
4-482.000.690.190.140.11322
6-402.130.750.250.170.13323
8-362.380.940.280.220.17323
10-322.501.000.310.260.19323
1/4-282.721.130.380.320.24323
5/16-242.941.250.440.380.29433
3/8-243.161.440.810.320.29433
7/16-203.381.660.440.370.28433
1/2-203.591.660.500.430.32434
9/16-183.811.810.560.480.364----
5/8-184.031.810.630.540.414----
3/4-164.472.000.690.650.494----
7/8-145.132.500.810.800.604----
1-125.442.560.880.900.674----
1-1/8-125.752.561.001.020.774----
1-1/4-126.063.001.061.110.836----
1-3/8-126.383.001.131.230.936----
1-1/2-126.693.191.131.310.986----
Metric Coarse
M2X.446.0412.704.773.5802.800322
M2.2X0.4547.6214.294.763.5802.790322
M2.5X0.4549.2115.884.763.5802.790322
M3X0.550.8017.464.763.5802.790322
M3.5X0.653.9819.056.354.2703.330323
M4X0.760.3222.226.354.9303.860323
M5X0.863.5025.407.946.4804.850323
M6X169.0628.589.528.0806.040423
M7X174.6131.7511.119.6807.260433
M8X1.2574.6131.7511.119.6807.260433
M10X1.585.7242.0711.119.3206.980433
M12X1.7591.2842.0712.7010.9008.180434
M14X2102.3946.0415.8813.77010.31043--
M16X2107.9550.8017.4614.99011.23043--
M18X2.5119.0656.3619.0517.70013.2804----
M20X2.5124.6256.3619.0519.30014.4804----
M22X2.5130.1863.5020.6420.32015.2404----
M24X3138.1165.0922.2222.76017.0704----
M27X3146.0565.0925.4025.98019.4604----
Metric Fine
M8X174.6131.7511.119.6807.260433
M10X180.7136.5110.328.2006.150433
M10X1.2585.7242.0711.119.3206.980433
M12X1.2591.2842.0712.7010.9008.180434
M12X1.591.2842.0712.7010.9008.180434
M14X1.596.8446.0414.2612.1909.140434
M16X1.5107.9550.8017.4614.99011.23043--
M18X1.5113.5150.8017.4616.56012.4204----
M20X1.5119.0656.3619.0517.70013.2804----
M22X1.5130.1863.5020.6420.32015.2404----
M18X2113.5150.8017.4616.56012.4204----
M20X2124.6256.3619.0519.30014.4804----
M22X2130.1863.5020.6420.32015.2404----
M24X2130.1863.5022.2222.76017.0704----
M27X2138.1165.0925.4025.93019.4604----
M30X2146.0565.0926.9928.14021.1106----
M39X2177.8080.9631.7536.32027.2306----
M36X3169.8680.9628.5833.15024.8706----
M39X3177.8080.9631.7536.20027.2306----