VP of Business Development—Rod Locks & Press Safety,
Machine Design Components
Product Manager, Rod Locks & Press Safety
A rod lock is an attachment to a hydraulic or pneumatic cylinder and buyers often wonder why the attached rod lock costs more than the cylinder itself. When you look at the logistics of making a rod lock versus making a cylinder, the manufacturing process of a cylinder is more straightforward than the process for a rod lock. Cylinders involve cutting material to length and then machining them with a few other modular components; whereas rod locks, involve more of a robust and precision-based process to handle heavy forces.
BUT WHY ELSE WOULD MY ROD LOCK COST MORE THAN MY CYLINDER?
Product construction is the main factor. A rod lock is constructed of more components that involve higher precision and are harder to make including:
- Precision-machined housing
- Hardened and ground clamp system
WHAT OTHER PRICE FACTORS ARE THESE FOR AN AMLOK OR SITEMA SOLUTION?
It comes down to application—whatever your application may be—that’s what is going to drive your costs. Other things that may drive your costs include:
Specialized Applications and Installation Requirements
Some applications require a custom design or unique installation specifications that can drive up the costs. Whether it’s for extra labor for installation services or for certain design features for unique applications, the more customized the product, the more expensive it tends to be.
Level of Holding
More holding requires a higher price due to the scaling up of the components that make up the product.
type of materials needed
Sometimes basic materials just won’t cut it, so specialized materials are used for certain environmental conditions or specialized applications. For custom units that need to hold 1500 lbs+, bigger springs can be added but they’re going to cost more. To prevent corrosion and rust, stainless steel can be used, but again, it’s going to drive up the costs.
- Stainless Steel
- Electroless Nickel Plating
- Special Seals such as Viton
Environmental conditions can drive the price up and change the materials that are necessary; for example, special designs may be needed for harsh environments. If your applications require resistance to something, like salt spray, special seals and a stainless steel or electroless nickel plated housing can be used. Our team can work with your application needs to drive the right solution, typically at a higher cost, to meet your needs.
diameter size of rod/cylinder
As mentioned earlier, a larger diameter equals higher holding and requires more raw material, which means more expenses.
In some applications, designers will attempt to use an existing rod or cylinder for mounting the locking device. In many cases, the existing equipment may be oversized compared to the actual load exerted on the locking device. This situation can produce higher prices for the locking device.
In certain applications, a separate rod may be integrated with the AMLOK due to limited mounting space. Typically, SITEMA safety catchers are mounted on a separate rod because the catcher is only to protect gravity fall conditions and not required to hold the tonnage of the press.
Mounting arrangement costs can increase due to the machine configuration. For example, sometimes two lighter-duty catchers must be used rather than one large unit. This is due to the machine configuration.
The most common practice for mounting a catcher is to bore a hole through the crown of the press and attach a rod to the platen.
Custom solutions require time, problem-solving, critical thinking in design, and possibly prototyping—all services that incur cost beyond the price of the unit.
Customs, freight, and fees also affect the price.
TOTAL COST OF OWNERSHIP (TCO)
After reading all this information on costs, it may seem like the initial expenses of power-off clamping units are high. However, rod locks and SITEMA solutions are more flexible and can be swapped out and repaired multiple times as long as the housing remains in good shape—providing a higher ROI and lower total cost of ownership—for roughly half the price of a new one you can repair your rod lock keeping the costs of ownership relatively low.