We often get inquiries for K-wires with little understanding of the options so I will try to lay out what our typical customer purchases and the cost differential between options. When someone refers to a “K-Wire” they each tend to think that there is a standard design for this type of product. My understanding is that “K-Wire” refers to a certain type of medical procedure, typically a wire used to fixate a bone fracture. So the design of a “k-wire” can vary dramatically depending on what type of procedure is being done.
The two most basic kinds of materials used in K-Wires are Stainless Steel and Nitinol. Stainless steel is the most common material used. Stainless steel tends to be more stiff while nitinol is durable. Nitinol has many additional properties of medical interest – http://en.wikipedia.org/wiki/Nickel_titanium. Nitinol typically costs about 4 times as much as stainless steel with all else equal. If you are trying to quote out a certain diameter but you are flexible, let the manufacturer know this. Often manufacturers will have stock material laying around which they can quote you a lower price for. This especially comes into play if you are doing a small prototyping run.
The most typical k-wire profile includes a trocar tip on one end, a short thread (approximately 1 cm) and a radius tip on the second end. Modern Grinding doesn’t stock K-Wires, we only make them to customer specification. In order for us to stock them we need an FDA approved design.
We have made k-wires with a double flat on the second end for drilling. We have made fully threaded k-wires. Clients have asked us for a “k-wire” with two blunt ends. I personally wouldn’t refer to that as a “k-wire” just a wire with two blunt ends.
K-Wire Electropolishing and Laser Marking
About 20% of our customers will get some sort of post process on the K-Wire. This is most commonly electropolishing and laser marking. Electropolishing is a subtractive process which brings out a chrome like shine on the Stainless Steel. Laser marking can include depth markers along the length of the wire. It can also include a unique identifier on the K-Wire.
If you don’t know what type of threads you would like, ask the manufacturer what they typically use based on the wire size you are using. If you request a specialized thread, it will end up costing you more. Threads need to be profiled into the grinding wheel or die that is being used. If you use a typical thread, the manufacturing company most likely has the tooling for the job.