Producing a good quality knife is a very labor intensive process. Generally speaking, lower quality knives will rely more on machines and automation to be produced while higher quality knives will involve more steps in the process and will require more hand work, which of course, means a higher price. Different brands of knives may go through somewhat different procedures but the basic process is pretty much the same. Following are the steps that Buck Knives uses to make a knife:
1. Laser Cutting or Fine Blanking
First, the blade must be cut out of raw steel. Buck Knives uses raw steel in two forms--plates and coils.
Plate stock - used for the larger knives that typically require thicker blades or higher hardness and edge retention. Blades and metal knife components are cut out of steel plates through the use of a computer programmed laser.
Coil stock - used for the smaller knives that typically have thinner blades. Blades and knife components are cut out of steel coils through a process known as "fine blanking" that uses a specifically shaped die to press the blades out of the raw steel coils.
2. Rough Grinding
The first step created the blade. Now, both sides of the blade are ground to achieve a desired blade thickness through CNC machining (computer numerically controlled).
The next step in the process is stamping. Depending on the model, stamping might include special features, such as a nail notch or groove. All blades are stamped with the Buck information-the Buck name, the model number and a date code.
Heat-treating is the process by which the cut steel blades are prepared to make them suitable for their end use in a specific type of knife. Heat-treating imparts special qualities to metals, such as hardness, strength, ductility and others. When heating and subsequent cooling are applied to metals in their solid state, the physical and structural properties of these metals are changed (but not the chemical composition).
Since different steels are used for different types of knives, they require slightly different heat-treating processes to acquire the desired properties. Buck works with state-of-the-art metallurgists who determine what heating and freezing processes are necessary to get the maximum performance from the different steels.
One of Buck's great resources is Paul Bos, who has been performing heat-treating since 1956. Paul is a nationally known heat-treating authority and has developed proprietary processes. Paul's link to Buck Knives goes back to the late '50s when he worked on custom knives for Al Buck. Paul oversees all of Buck Knives' heat-treating and performs heat-treating for a great number of custom knife makers. His shop is located in the Buck plant, where he is readily available to consult with Buck's engineers. Clearly, the Paul Bos touch is an integral part of Buck's great blades.
Buck Knives takes each blade through a carefully controlled three-step heat-treating process that brings the blade to a blend of properties appropriate for the end use of the knife. To ensure uniform heating, the blades are separately laid out on a continuous, slow moving conveyor belt.
First, the blades are heated to a high temperature (then cooled to room temperature).
Next, the blades are lowered into a cryogenic freezer where they are subjected to below zero temperatures (then brought back to room temperature).
After that, the blades are placed in an oven where the temperature is slowly raised to between 350°F to 950°F, depending on the end use and steel type.
This tempering process toughens the steel and brings 420HC blades to 58 on the Rockwell scale, the preferred hardness for edge holding. ATS-34, BG-42 and S30V blades can be hardened to Rc 59.5-61. To achieve the desired properties, some blades are tempered more than once. Only after this rigorous heat-treat process is a Buck blade ready to be edged-the other vitally important process in creating a great blade.
5. Close Tolerance Grinding
After heat-treating, each blade is fine ground (both sides) to a close tolerance through CNC machining. This step gives each blade a consistent thickness so it will fit with all the other knife parts for that model.
6. Blade Finish
Depending on the desired appearance for the blade, it may be rough tumbled to achieve a satin finish or fine polished to achieve a bright, shiny finish. To some extent, this step smoothes out the marks created during the grinding process.
7. Hollow Grinding
The next step in blade making is the hollow grinding process. Here, blades are ground (computer machined) to achieve a desired shape and slope from the top of the blade down to the cutting edge at the bottom. Predominantly, we use a "semi-hollow" grind to create an edge that will be sharp out of the box, retain its sharpness, be easy to re-sharpen and enable the blade to maintain its strength. Robotics is used for grinding to achieve a consistency not possible with hand grinding.
8. Final Grinding
In this step, some blades receive grinding for special features, such as serrations, gut-hooks and chamfers. As with previous grinding, this is a CNC step (computer numerically controlled).
The knives are assembled using various processes, materials, fasteners and adhesives, depending on the model.
Some knife models (in particular, knives with natural handle materials-wood, bone, etc.) go through a shaping process whereby the handle materials are ground, sanded or buffed to achieve a smooth fit and finish. Models with metal handles (and most plastic handles) may not go through this stage. Tactical knives would be an example of knives that do not require the shaping stage.
For those knives that went through the shaping stage, next they get fine polished (handle materials).
Edging the blade with Buck's Edge2x™ Technology.
For 35 years, Buck Knives followed a blade-edging protocol that produced blades with excellent edge-holding qualities. In 1999, Buck decided to edge out the competition with the most exciting innovation in edge technology-Edge2x.
Chuck Buck, along with Buck engineers, quality and production supervisors, and experienced blade edgers, experimented with angles and materials before coming up with the exact edge geometry specification to create this new, thinner, sharper edge. This edge was achieved by changing the included angle (the total of the angles on both sides of the blade) from a range of 35° to 50° to a range of 26° to 32°. This range allows Buck greater flexibility to match the angle of the blade to the function of the knife.
The initial part of creating the edge is performed during step #7, hollow grinding, which is a computer controlled, automated machine process. During this grinding process, blades are tapered to a specific profile. This yields a consistent blade thickness at the edge that cannot be duplicated by hand.
Then the human hand takes over on an edging wheel. Another key to the success of the Edge2x process is that we converted to using laminated leather stropping wheels instead of stitched cloth. The sturdiness of the leather wheels enables us to eliminate "rollover" (where the edge can lose its ideal keenness) and create razor-sharp blades with consistency.
The human touch lessens the risk of burning, which can lower the hardness of the steel. Experienced edgers, who have been with Buck for many years, went through extensive training to learn the new system. It took many months for them to perfect the process, but it has been well worth the effort.
A computerized test for edge retention, developed by CATRA (Cutlery and Allied Trades Research Association), is performed on blades for each knife model. For inspection, a laser-measuring device, called a goniometer, is used to check the precise angle measurements to verify that the edge matches specifications. Edge2x blades have been compared against our older Buck blades and evaluated using the CATRA tests, which proved the superiority of our new edging process.
With Edge2x Technology, every knife made by Buck is sharper out of the box, holds an edge much longer and is easier to re-sharpen when needed.
In the same way the blades are finish-edged by hand, blades are sharpened by hand on a sharpening wheel. Each blade is tested for sharpness.
Each knife is given a final cleaning and lubrication prior to being packaged.