Mechanical Clamps

Mechanical 1/4 Turn Quick Set Clamps

Mechanical Quick Set Clamps

quick-set-clamp-photo

When to Use 1/4 Turn Quick Set Clamps:

Use mechanical quick set clamps with dies having slotted die plates and enough over slot clearance for the set clamp body.  U-Slot brackets or ears may also be added to the dies or a heel block added to the back of the clamp for some applications.

How they work:

To use, move clamp into position and manually hand tighten nut using the large diameter knurled surface.  Use a wrench to torque to the desired preload.  The large bronze alloy nut acts as an easy turning, anti-galling, large surface thrust bearing arrangement for superior performance.

Model 255 clamps require approximately 125 ft.-lbs. of torque to preload the clamp to 10,000 lbs. clamping force.  Model 259 clamps require approximately 350 ft.-lbs. to preload clamp to 20,000 lbs. clamping force (unlubricated threads).  Clamp preload should be limited to 20,000 lbs. and 40,000 lbs. respectively.

Options and features:

ARA vs. FRA.  Free Rotation (FRA) clamps use standard threaded bolts, while Anti-Rotation (ARA) models use modified threads to prevent the clamping plate from spinning about the bolt.

TSB vs. STN.  Forged T-Slot Bolts (TSB) are standard for production units.  In the case where a larger than standard clamp range is desired, the stud and T-Nut option (STN) is available.

HB Option.  In cases where customers desire to use the clamp in applications without slotted die plates, a heel block may be added to the clamp to support the back of the clamp.  (Clamping force is 50% of rating.)  For this option specify HBX.XX at the end of the part number.  (X.XX = clamping plate height in inches.)

Nut Retention Option.  In cases where customer desires to prevent the nut from coming off the bolt.  A stop mechanism is added to the top of the bolt.  Use TSL in place of TSB in the part number for this option.

Applications/Sizing

Standard Configurations

Model 255 clamps are designed for 3/4” T-Slots and Model 259 for 1” T-Slots. The part number references the “bolt length”, which is not the clamping height, but rather the complete length of the bolt. The charts show nominal clamping height for standard T-Slots. The bolt length can be selected for the part number below.

Model 255
TSB Nominal Clamp Height**
Clamp Range B*
(Standard 3/4” Slot)
Min.     Max.
A+B*
Min.     Max.
CDE
0 – 10”1.125”.75”2.0”2.0”2.5”4.0”
1 – 2.875”2.125”1.75”3.0”2.5”5.0”
2 – 31.875”3.125”2.75”4.0”2.5”6.0”
2½ – 42.375”4.125”3.25”5.0”3.0”7.0”
3 – 52.875”5.125”3.75”6.0”3.5”8.0”
3½ – 63.375”6.125”4.25”7.0”4.0”9.0”
Model 259
TSB Nominal Clamp Height**
Clamp Range B*
(Standard 1” Slot)
Min.     Max.
A+B*
Min.     Max.
CDE
0 – ½0”.6”.75”1.6”2.4”2.5”4.0”
¾ – 1½.75”1.6”1.75”2.6”2.5”5.0”
1¾ – 2½1.75”2.6”2.75”3.6”2.5”6.0”
2¼ – 3½2.25”3.6”3.25”4.6”3.0”7.0”
2¾ – 4½2.75”4.6”3.75”5.6”3.5”8.0”
3¼ – 5½3.25”5.6”4.25”6.6”4.0”9.0”

* T-Slot neck height (dimension A) is assumed to be .875” for 3/4” slots and 1” for 1” slot.

** TSL Style with retaining ring incure a 1/4” reduction in maximum clamp height.

Suffix – STN may replace – TSB if fully threaded stock and T-Nut is cleared for no minimum clamping heights.  Maximum clamping height for STN is calculated as follows:
Model 255 BMAX = E – 3.25
Model 259 BMAX = E – 4.00

Quick Die Change QDC Quick Set turn Clamp Lightning fast Time Saver when installing dies
Quick Die Change QDC Quick Set turn Clamp Lightning fast Time Saver when installing dies - part number specification
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