Salt Lake City, UT--A high-strength alloy designed for aerospace has reached another lofty peak. The space-age material now makes it safer and easier for ice climbers to scale some of the world's highest and most defiant mountains.
For the high-end climber, Black Diamond Equipment Ltd. developed what it claims to be the ultimate ice pick--a "stinger" pick made from a special double-vacuum-melted alloy that combines high tensile and shear strength, high fracture toughness, and fatigue resistance.
The original pick, with a well-designed, compound-curved shaft, was made of 4340 chrome moly steel. However, it was prone to breakage and point wear, particularly when the climber hit or smashed the point on rock under the ice veneer.
"Some climbers would go through five or six picks a season," recalls Ken Stone, Black Diamond materials engineer. "Prior to eventual replacement, they had to file points to restore their sharpness, until they were no longer serviceable."
Then Black Diamond turned to AerMet(TM) alloy supplied by Carpenter Technology Corp. (Reading, PA). Developed as a candidate for the landing gear of U.S. Navy carrier jet fighters, the alloy combines properties also found useful in many commercial applications. When heat treated, it can attain typical tensile strength of 285 ksi (1,965 MPa), with fracture toughness in excess of 100 ksi (square root)inch (110 MPa (square root)m). Being air-hardenable, the alloy remains virtually free of thermal distortion. This is a bonus for anyone who makes parts with complex shapes or critical size tolerance, such as the ice pick.
Stone reports that the extra strength of the picks made from AerMet allows for a 20% thinner pick. This design improvement, in turn, allows the climber to make better penetration with less ice and rock displacement, achieving "superior hookability" in fissures.
The idea in ice climbing is to set the pick in the ice with the flick of a wrist, not a hammer swing, Stone explains. With minimum effort, using a strong but light pick, the climber wants to get deep, solid penetration, displacing as little ice as possible. Controlled, accurate tool placement--a function of tool design--maintains the climbing rhythm.
Stone adds that ice tools must function reliably in "mixed climbing," the big trend in a fast-growing sport. Climbers must use the tool, or ax (with the pick as the working member), to traverse over both ice and rock. The climber hooks on rock, then inserts the pick into fissures to swing or pull into a new position.
The newly designed stinger pick has become the preferred tool by the most experienced climbers, Stone notes, adding: "We're having a problem keeping up with demand for the new pick. Everyone in the field, including our technical reps, are providing nothing but favorable feedback. It seems that climbers, as a breed, are always looking for gear that is bombproof."