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Maximizing the physical properties of diamond through exceptional craftsmanship, sophisticated equipment and customized engineering, DDK's longer-lasting, diverse line of knives feature precise edges and an unconditional guarantee.
Blade Angle Selection | Knife Care and Use | Knife Selection


All diamonds used are gem-quality with pale yellow or better color. Raw diamond is free from inclusions and shows only minimal stress under polarized light. Near-perfect octahedral crystals are chosen so that internal structure is optimal.

Selected diamonds are cleaved for PERFECT orientation with the desired crystalline plane. This orientation allows us to polish parallel to the final edge providing a perfect edge with superb durability. DDK Diamond Knives regularly last for many years before requiring resharpening.

Diamond slabs are mounted in bronze using a powder metallurgy technique to prevent looseness. The slabs are oriented to leave a large amount of diamond in the shank insuring a tight grip and leaving a large resharpening reserve. In this way, DDK can guarantee unlimited resharpenings. If your diamond ever becomes loose in its shank during resharpening, the knife will be replaced with a new one at the resharpening price.

Diamonds are sharpened using the finest diamond powder and most accurate lap spindles available. Angles are measured and facets ground with 0.1° precision to insure desired orientation.

Boat are made of anodized aluminum or stainless steel and fit all brands of ultramicrotomes without an adapter. Black is chosen to enhance the visibility of floating sections. All materials are suitable for use in both cryo and room temperature applications.

The epoxies used to seal the boat and firmly hold the knife in place will not loosen or corrode and are impervious to all solvents. These epoxies are hydrophilic insuring adequate wetting of the diamond's edge during cutting.

Clearance angles are preset at the factory for a microtome setting of 4° . Other clearance angles and boat colors are available upon request.

DDK Diamond Knives are tested by cutting silver to blue sections and examining them with the electron microscope at 2000X and 20000X. The entire edge of every knife is tested in this way. Custom testing protocols are performed upon request.

Your satisfaction is unconditionally guaranteed with DDK Diamond Knives. Please inspect promptly after receipt but if your knife does not perform to your expectations, return it for replacement, repair, or refund.

Your resharpened DDK or DuPont Diamond Knife will have the same edge length and cutting edge and carry the same guarantee of quality as our new diamond knives. Only by having your DuPont or DDK knives resharpened by DDK can you be assured of having a knife made to these rigid specifications. All other resharpening services REPLACE the original knife with one of their own manufacture when you have ordered a resharpening.