
SIGMAFORGE® is one piece precision forging used in manufacturing several ZWILLING J.A. HENCKELS TWIN® knife series including TWIN® Four Star II, TWIN® Select, TWIN® Pro "S", TWIN® Five Star, and Four Star. SIGMAFORGE knives are forged from a single piece of steel and have the following benefits:
Shown below are examples of SIGMAFORGE knife series; TWIN® Pro "S" and TWIN® Four Star II
TWIN® Pro "S"

TWIN® Four Star II

Traditional Hot Drop Forged Process:
The Traditional Hot Drop Forged Process is used exclusively for the TWIN® Cuisine knife series. TWIN® Cuisine knives, through this process, are also constructed from a single piece of steel. Due to the exclusive horizontal design of the tang, the knives can only be manufactured through this process. This construction also results in a heavy weight - durable knife, and the patented TWIN® Cuisine handle design (U.S. Design Patent No. D524,121). Of course these knives are also Friodur® ice hardened for maximum no-stain properties and more blade strength.
TWIN® Cuisine

Stamped:
TWIN® Signature and TWIN® Gourmet knives are constructed through a one piece, fully stamped process. This construction provides for excellent cutting performance and sturdiness.