Hydraulic Clamping

Hydraulic clamping is used in production CNC machine shops as an automated or semi-automated way to secure components to the workholding surface. Hydraulic clamping allows for substantially reduced load an unload times, which in turn allows for higher capacity utilization of machines. Hydraulic clamping also improves overall quality of the manufacturing process by providing consistent clamping force that is completely repeatable.

Hydraulic Clamp Manufacturers

• Kurt Workholding manufactures the industry standard Kurt Vises for machining. Among the Kurt workholding solutions are hydraulic clamping systems that include a variety of swing clamps with a clamping capacity from 475 lbs to 6,000 lbs. All Kurt Workholding vises and hydraulic clamps are backed by the Kurt Ironclad Warranty.

Manual vs Hydraulic Clamping

The primary advantage of hydraulic clamping in a production environment is the increased efficiency from time savings -- which must be great enough to offset the capital cost of purchasing the hydraulic clamping system in the first place. In general the shorter the work time is on a piece, the more benefit there is from using a hydraulic clamping system. For example, consider an 8 hour shift and a part that requires 2 minutes for load and unload via manual clamping, and 1 minute for load and unload via hydraulic clamping (not automated). Here are the total number of parts that could be produced in an 8 hour period given the time required to machine the part:

Part Production Time	# Parts via Manual Clamping	# Parts via Hydraulic Clamping
1 hour	7.74	7.86
30 minutes	15.00	15.48
15 minutes	28.23	30
5 minutes	68.57	80
1 minute	160	240

 It quickly becomes apparent that the advantage of hydraulic clamping is inversely proportional to the production time required to machine a part. For complex machined parts a hydraulic clamp will have virtually no benefit, but for fast production components the load/unload time becomes the majority of the time spent on the manufacturing process. For these short production time components hydraulic clamping can have a vast improvement on the production capacity of a single CNC machining center. This benefit grows enormously as the production time decreases below a minute.

The following video highlights the difference between manual clamping and non-automated hydraulic clamping for a short production time project:

Automated Clamping Systems

Hydraulic clamping also allows for semi-automated or fully automated clamping systems. These system offer the ultimate in production uptime, consistent clamping pressures, and reduced need for labor overhead. These systems can often be semi-robotic, in which a fully automated system places raw materials into the machining centers, a hydraulic clamping system locks the material into place, and after machining the same system releases and unloads the finished part.

This kind of fully automated hydraulic clamping system is appropriate for high speed machining centers that are manufacturing very large quantities of parts that require relatively short production times per part (production times measured in minutes, rather than hours).