Steel Plane Blades
by Don Naples

There are many types of steel used in making plane blades. Each type is designed for a particular purpose. Harder steel blades provide a more durable edge and don’t require sharpening as frequently as softer steel blades. Hard steel blades do require care, as they are more susceptible to chipping at the edge than softer steel blades. Blade manufactures produce blades of a particular hardness, measured on the Rockwell “c” scale, and of a material alloy that meets the requirements for the blade purpose and intended resale price. That is why there is such a large price difference between a high quality Japanese or Hock plane blades and the ones found in a Craftsmen or other low cost planes. Which one is right for you, depends on the application and the price you are willing to pay for a level of quality. As usual, you often get what you pay for.

There are exceptions to expensive hard steel blades, as a woodworker can often find real bargains of old cast steel plane blades. These are available through sellers of old tools, like Pete Niederberger (pniederberger@aol.com), or on eBay. Often, the bodies of these planes are boat or coffin shaped, and do not have the feel or narrow throat of a modern plane. Cecil Pierce wrote an excellent article in American Woodworker magazine dated February 1995 #43 about making plane bodies that designed to use these cast steel blades. These cast steel blades are commonly laminated, as are Japanese blades. This design provides hard steel, used at the cutting edge, forged onto soft steel which makes up the rest of the blade body. One should not hollow grind these blades, as it makes the hard steel thin at the leading edge and more susceptible to breakage. This is why you see Japanese blades with flat grinds on the bevel, never hollow grinds. The same applies to laminated cast steel blades. If you are not sure if the blade is laminated, polish the bevel edge and look for a different coloring and a line horizontally across the face of the bevel. It is fairly easy to see, as the harder steel abrades differently and holds a higher polish than the softer steel. Using a plane made with these thick hard steel blades, provides less chatter of the blade, due to the thickness, and the hard steel holds a particularly fine edge that is longer lasting than softer steel blades. You will readily see the difference in the performance in your planing with these blades.

Infill planes, such as those produced by Spiers, Mathieson and Norris, using cast steel blades, are fairly rare, and are usually expensive. There are a few current manufacturers of infill planes. There are also infill plane kits manufactured for the user to assemble and fit and finish. Infill planes are fairly heavy and their bulk aids in planing flat smooth surfaces. These planes are also available from resellers of old tools such as Pete Niederberger and others.

 

New blades such as the ones produced by Ron Hock, are not laminated, but use high quality steels and processes such as cryogenically treating the steel, to produce a tough cutting edge. Ron offers thick steel blades that are often fitted into plane bodies made by the user. An article in Fine Woodworking October 1997 #126 written by David Welter of the College of the Redwoods explains how to make this style of plane.

 

If you have planes that use thin blades, the blade is more susceptible to flexing as it attempts to shave wood. An old design that was made to minimize this vibration is the Stanley Bed Rock plane. These planes have a flat machined surface where the plane frog mounts to the bed of the plane as compared to the Bailey design which has three small points of contact for the frog to rest on the bed of the plane. The numbering of these planes is from #602 through #608 as compared to the Bailey style, which is from #1 through #8. Lie Nielson planes copy the Stanley Bed Rock design and have thick blades which additionally reduce vibration of the blade.

 

All planes benefit from being well tuned and having a sharp and properly honed edge. A sharp edge can not be achieved by merely sharpening the bevel, but must have the back flattened to achieve the best performance. If the back of the plane blade has machining marks from its production process, it will provide a seriated edge if not first flattened. A flat back that meets a well honed bevel edge will provide a truly sharp edge and gains the user the best performance from that tool. How well the edge holds up to use, depends on the hardness of the blade.

 

A well tuned plane can enable its user to achieve a quality of workmanship not attainable with using just power tools. Putting a one degree bevel on a cabinet door edge, fine tuning the fit of a drawer, or planing the surface of a highly figured wood will demonstrate a few of the benefits achieved with these fine hand tools.