Knife Making

TTAK Benchmade Factory Tour, Part I: Making The Blade.

Image courtesy maps.google.comI’m lucky to live only 20 miles from Benchmade Knives’ one-and-only factory, located in Oregon City, Oregon. After I missed meeting him at the SHOT Show, Benchmade’s Derrick Lau invited me for a factory tour. Joe Grine joined me for a dazzling “How It’s Made” walk-through of Benchmade’s entire production process, from stacks of exotic sheet steels all the way through to final sharpening and packaging.

It was one of the more amazing afternoons I’ve ever spent. And of course we took a ton of pictures.

Raw Materials

Image: Chris Dumm

Benchmade knives all start as raw materials on their parts shelves, like these sheets of G10 and winewood. I hope you don’t mind that we didn’t take pictures of the miles of thin bar stock and various rolled sheet metals which go into their liners and fasteners.

Image: Chris Dumm for TTAK

Here are some slabs of presentation-grade cocobolo wood, destined for different knife scales. Another wall of (very sturdy) shelves holds sheets of just about every blade steel you can imagine: CM154, S30V, 440C, M390, D2, and N680 were just a few of the ones I immediately recognized.

Benchmade doesn’t source their finished components from anywhere else, and the only job they subcontract is specialty blade coatings. Everything else is made and done on their own factory floor. Even the tiniest opening studs are turned (not stamped) from various grades of bar stock, on a row of CNC lathes.

Blank Cutting

Image: Chris Dumm for TTAK

All of those sheets of supersteels will eventually find their way into a laser cutter like this one, where they’ll be turned into blade blanks.

Image: Chris Dumm for TTAK

The immediate result is a sheet of blanks like this. The cutter leaves a tiny sprue connecting each blank to the sheet until a machinist knocks them loose with a padded mallet. The sprue is usually formed on what will eventually become the blade’s edge, since most of that metal will be removed in the milling and grinding operations.

Image: Chris Dumm for TTAK

This ‘grating’ is all that’s left of the sheet after the laser cutter is done with it. Because the raw steel hasn’t been heat- or work-hardnened by the laser cutting process, these sheets are sent back to the steel supplier to be melted into new sheets of exotic steel. Waste not, spend not.

Milling

Image: Chris Dumm for TTAK

The blade blank comes out in this form. This one has been drilled already, and from here it’s a short walk to the milling machine which grinds the blanks to the desired parallel thickness.

Image: Chris Dumm for TTAK

Obviously these blanks aren’t destined for the same model of knife, but here’s a before-and-after of what the milling process does. Benchmade built their own milling machine for this operation, and we respected their wish to keep at least some of their secrets actually secret.

Grinding/Polishing

Image: Chris Dumm for TTAK

The newly-milled blanks are then ground with their primary bevels. Derrick explained to us that hollow grinds are much simpler to do than multi-bevel tantos like this one. Each bevel requires a separate grinding operation, and a hollow-ground blade needs only one.

Image: Chris Dumm for TTAK

After another QC check (and there are many) the freshly-ground blades are given an initial polish in giant tumblers full of ceramic media like this. This isn’t the only polish, but this is one of the last stages before the blanks are heat-treated.

Heat-Treating

Benchmade does their own heat-treating, which is a slow and highly proprietary process. Since it consists of heating and cooling the blade blanks at very precise intervals and temperatures, it’s not terribly exciting to watch. I hope you’ll pardon us for not taking a picture of watching metal cool, but it’s a bit less interesting than watching paint dry.

Final Fitting And Polishing

Image: Joe Grine for TTAK

The hardened steel blades are now more than ‘blanks’, and they’re ready for their final polishing along the spine (shown here) and a final spin in a media tumbler. The back-polishing is all done by hand, using jigs which can finish several blades at once.

Plain steel finishes like satin, stonewashed, and bright-polished blades are all done in-house, but Benchmade farms out blade coatings to a subcontractor a few miles away.

Once the blades have their external finish done, they’re ready for assembly.

Next Installment: Scales, Grips And Liners

In Part II we’ll follow the stamping and finishing of the liners and scales, the other major components of a folding knife. Stay tuned!

Discussion

7 responses to ‘TTAK Benchmade Factory Tour, Part I: Making The Blade.

  1. Am I the only one with an irrational desire for one of those “grates”? That would look awesome hanging up in my garage.

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