CPM-20CV vs MagnaCut.

The same rating word for edge and rust, and the same window

CPM-20CV and CPM MagnaCut carry the same rating word, excellent, on two of the three properties these records rate: edge retention and corrosion resistance. A shared word is a coarse match, not a measured tie, and the two edge lines are not identical. The CPM-20CV entry credits its rating to a high carbide volume and adds "top-tier wear resistance"; the MagnaCut record gives the one word and names no cause. Both records name Crucible Industries as the maker and type the steel as a powder metallurgy stainless, so the steelmaker does not separate them. CPM-20CV's maker line also ties its composition to Bohler M390, a match the CPM-20CV vs M390 comparison covers.

The hardness windows do not split them either: both published windows read 60 to 64 HRC, and no listing on this page gives a hardness for its blade. Hardness offers no shortcut between these knives. For a buyer weighing the two steels, the rating words agree on edge and rust, and what the records leave to choose between is wear resistance on one side and toughness on the other.

Two opposite recipes for the same rust rating

Corrosion resistance is level at excellent, but CPM-20CV and CPM MagnaCut reach that rating from opposite directions. The 20CV record credits very high chromium, about 20 percent of the steel. The MagnaCut record lists about 10.7 percent chromium and says the steel was engineered to keep it "in solution rather than locked into carbides", so the chromium it has stays free to resist rust. One recipe relies on a large supply of chromium; the other relies on where a smaller supply ends up.

Toughness is where the two recipes part, and the 20CV record names the gap itself. It rates 20CV's toughness as good for a steel of its hardness and wear resistance, "though not as tough as MagnaCut." The records stop there. They put no number on the gap, so they give a direction, not a size. On paper, then, rust does not decide this choice. What decides it is which an edge needs more: wear resistance through long abrasive cutting, or margin when it meets something hard.

The Gerber Savvy and the Hogue Deka, with Case alongside

Three makers stand behind the knives named here, Gerber and Case on the CPM-20CV side and Hogue on the MagnaCut side, so a change of steel here is also a change of maker, blade shape, lock and handle. The Gerber Savvy Pivot Lock has a 3.5 inch stonewash CPM-20CV Wharncliffe blade, a gray aluminum handle and a pivot lock, 4.5 inches closed. The Hogue Deka ABLE Lock has a 3.25 inch tumbled finish MagnaCut clip point and a black polymer handle, and folds to 4.25 inches. The Savvy brings the longer blade and a Wharncliffe profile, the Deka a shorter clip point, and the Savvy costs more than the Deka.

The Case CPM-20CV knives named here both carry a micarta handle and bolsters. The Case Highbanks Slip Joint pairs a stonewash 20CV modified Wharncliffe blade with a black burlap smooth micarta handle and closes to 4 inches; as a slip joint, it has no lock. The Case Longhouse also closes to 4 inches, with a stonewash 20CV locking clip blade and an OD green canvas micarta handle. The Savvy, the Deka and both Case knives each give the origin as USA in their listings, so origin does not separate these knives. If the work calls for a lock, the Highbanks Slip Joint drops out whatever its steel, leaving the Savvy, the Longhouse and the Deka.

Abrasion suits CPM-20CV, hard contact suits MagnaCut

The choice between CPM-20CV and MagnaCut turns on the kind of wear an edge sees. Long cuts through abrasive material dull an edge by wear, and wear resistance is what the CPM-20CV record credits to its high carbide volume. Edges that catch on something harder than the work, such as a staple or a bone, test toughness instead, the margin an edge has against chipping, and there the 20CV record concedes the ground to MagnaCut.

So the Gerber Savvy or one of the Case knives named here suits a buyer whose work dulls an edge without chipping it and who wants the shape and handle those knives offer. The Hogue Deka suits a buyer who wants the same rating words on edge and rust with more margin when the edge meets something hard. Neither steel is the weak choice on rust or edge life by these records. The guide to CPM MagnaCut knives brings the MagnaCut side together on one page.