It doesn’t all come down to nuts and bolts. Specialty manufacturers of aerospace or automotive parts, medical devices, and packaging often must deliver precise amounts of torque to non-standard fasteners. The range of non-standard fasteners is broad enough to escape simple description, but examples include eye-bolts, clevises, oil filters, syringe caps, and even hex-head bolts and star-head bolts.
At the same time, these specialty products are often produced in small batches, well below a facility’s yearly or even quarterly capacity. This results in a high cost per unit for single-purpose specialty tools, which in turn raises the price point of your products, potentially diminishing demand or rendering your operation uncompetitive.
For a contract manufacturer regularly producing small runs of specialty products, the cost of retooling for each contract becomes prohibitive. Even if your operation regularly handles fasteners of different sizes, which still require different toolheads, purchasing separate tools for separate size fasteners is ungainly and expensive.
For service operations, which may routinely encounter myriads of different specialty heads and fastener sizes, purchasing a different tool for each application will prove to be an inefficient use of resources. Fortunately, the solution is simple—increase your versatility with torque wrenches built for interchangeable heads.
Choosing an Interchangeable Head Torque Wrench
Most torque screwdrivers are built to accept different head styles, and kits can be purchased with all conceivably useful heads. Wrenches, however, are a different story. Unless specifically stated in the product description, a torque wrench will most likely have a fixed head, usable only for a single size and type of fastener.
Interchangeable head torque wrenches will be advertised as such, and they are the preferred tools for operations needing to quickly shift between many different fastener styles. As interchangeable head torque wrenches are intended to be used on many different products, selecting the right wrench entails developing an accurate picture of the various expected and possible needs of your operation. To find the right wrench, you’ll need to know:
- The size ranges of fasteners you’ll use
- The head styles of fasteners you’ll use
- The torque values your fasteners require
- The specificity of your torque needs
Different wrenches are capable of producing different amounts of torque. Larger fasteners will require greater torque and larger wrenches. Also, different torque limitation mechanisms result in more or less specificity in fastening. For critical applications, break-over wrenches, which deflect 20-90° on reaching their set torque value, are preferred. For less critical applications, click wrenches, which inform but do not limit their operators when torque is reached, are a more cost-effective solution.
In addition, interchangeable head torque wrenches are subject to more stress than fixed head torque wrenches. While their connection is engineered to hold up under pressure, the joint is simply not as a durable as that on a solid state wrench. It’s the same reason a samurai sword is a single piece of metal, without a joint at the blade and the hilt.
As such, it’s wise to choose a quality manufacturer of sound repute, one that supports their products with warranties and service options. Buying one wrench instead of ten doesn’t help if you need to buy that wrench ten times.
Specialty Torque Wrench Heads for Unique Products
If a nut or bolt is in usage in the United States, a wrench head has been built to fasten it. So, for the most part, any fastener your operation needs to tighten can be handled by a pre-existing wrench solution. The vast majority of fasteners can be tightened by using open end, box end, flare end, hex key, strap, or other wrench heads already available.
However, sometimes an application will demand a unique fastener, not used elsewhere. Manufacturing or servicing such unique fasteners will not be possible with tools currently in existence. As such, a new tool must be built. An example could be needing to tighten a sensitive plastic syringe cap without causing damage. To tighten the cap (which stretches even the definition of fastener), a specially designed tool may be needed.
To procure a wrench head which isn’t currently in existence, you’ll need to request specialty engineering services from a qualified, capable tool manufacturer. Their engineering team will learn the precise needs of your fastening solution, prepare designs, offer a quote, and manufacture the tool to demand.
Because this process is far more labor-intensive than selling an existing tool and may require the manufacturer to reconfigure their equipment, it will likely be significantly more expensive than purchasing a tool from a catalog. So, a clear business case for manufacturing the product which requires a specialty fastener in the first place is an essential prerequisite to contracting special tool engineering services.
If your manufacturing operation regularly changes products or contracts, interchangeable head torque wrenches will reduce the amount of capital you need to invest in your tools. Be sure to consider the full range of fastening needs you may encounter as you select the tools for your operation. Certain, unusual circumstances may demand the creation of a new tool head for your application. If so, make sure your anticipated return on that product can justify the creation of a new, single-purpose appendage for your wrench. With these solutions, you can increase the versatility of your manufacturing operation in order to be prepared for any situation.
