Multi-Jackbolt Tensioners - Nut Style
Below are the available series. These are simply guidelines to choose the appropriate product for your application. When you contact us for a quote or to order, we will verify that the correct product is being purchased for your situation. Thank you for your interest!

Standard Series:
• MT
• CY
• MTSX
• SJX - Jjamnuts
• SMX - Mill Motor Nuts
• NI - Bearing Locknuts
• MTA - Armored
• CN - Crosshead Jamnut
• SP - Piston End Nut
• SX8 - Flexnuts
• SX12 - High Strength Flexnuts

Medium Temperature Products (-50ºF to 650ºF):
• H650
• H650X
• H650T
• H650TX

High-Temperature Products (650ºF to 1200ºF):
• H1215
• H1216
• H1218

H1215 - High Temperature Torquenuts™
• Operating Temp: 650ºF to 1200 ºF

• Description: H1215 Supernuts® have the smallest spotface design and will retrofit even the tightest nut spacing.

- Replaces “castle” and “acorn” nuts
- Smallest nut O.D., approx. 1.5x stud dia.
- Most number of jackbolts
- Smallest diameter jackbolts
- Lowest jackbolt torque
- For stud sizes up to 6” diameter and over

Prestress: Usually limited to 45,000 psi bolt stress.

• Application Examples: Turbine control valve, HP turbine and valve.

H1216 - High Temperature Torquenuts™
• Operating Temp: 650ºF to 1200 ºF

• Description: H1216 Supernuts® feature a slightly larger spotface than the H1215 Series. The H1216 is preferred to the H1215 if flange spotface room exists.

- Replaces many “acorn” & “castle” nuts.*
- Intermediate series, approx. 1.6x stud dia.
- Usually fewer jackbolts than 1215 series
- Some sizes have the same number of jackbolts as H1215 but of a larger dia.
- Some sizes can achieve higher preloads than the H1215 series
- For stud sizes up to 4” diameter

Prestress: 45,000 psi - 60,000 psi bolt stress.

*Usually the H1216 has a slightly larger OD than the original acorn or castle nut, but it can be used as long as spot face room is available on the flange.

• Application Examples: IP turbine, Turbine stop valve.

H1218 - High Temperature Torquenuts™
• Operating Temp: 650ºF to 1200 ºF

• Description: H1218 Supernut® Tensioners have the largest diameter of the three series. The larger diameter nut body permits larger diameter jackbolts, resulting in fewer jackbolts. This allows the H1218 to be installed and removed in the shortest time.

- Typically replace heavy hex nuts. Can also replace “acorn” and “castle” nuts if flange spotface room exists
- Largest nut O.D., approx. 1.8x stud dia.
- Least number of jackbolts
- Largest diameter jackbolts
- For stud sizes up to 2-3/4” diameter

Prestress: 45,000 psi - 60,000 psi. Higher prestress available with custom design.

• Application Examples: Turbine control valve, High pressure steam flange.