As with any edge tool, a hand plane's blade, or iron, is the key to its performance. Yet many people try to make due with their irons poorly tuned and sharpened. The irons on common planes usually need a significant amount of work before they will cut suitably, and then even more to cut really well.
Premium contemporary planes come with nicer irons that are substantially flatter, thicker, and sharper right out of the box, so they provide smoother performance without a lot of prep work. But for those that appreciate the classic appeal of more common planes, Lee Valley's replacement irons offer an instant upgrade to the new standard for quality cutters.
These Lee Valley irons are made to fit the more popular plane styles that Stanley Tools originated, and that Stanley, Record, Footprint, Kunz, and others produced throughout the last century. Modern versions of these tools are known for their less refined cutting components, and the older models might lack in metallurgical sophistication or just be in rough condition from decades of use or misuse.
Lee Valley's high quality O1 and A2 alloy irons are lapped on the flat side to a tolerance of 0.0002 inch, and they have precisely flat-ground bevels that only require a final honing to use.
Here is where many will think of the replacement like they think of a worn carbide-tooth saw blade: Should I keep the original and sharpen it, or should I invest in a new one? For this test, I had to do both, painstakingly reflattening and sharpening my old irons for hours to provide a fair basis of comparison. I also put the final honing on every iron in the test in the exact same way for consistency.
If most guys use only one plane, it is a block plane, so I first tried Lee Valley's iron for the Stanley #60-1/2. The vintage of the plane determines the replacement you need, so I chose to use my favorite oldest model. Since the bevel faces up on low-angle block planes, I didn't need to make a real adjustment to fit the 58% thicker iron to the plane. It clamped right in and cut very fine shavings from the cherry, maple, and knotty apple on which I tested each tool.
The upgraded iron is 0.125- inch thick and less prone to deflection compared to the original at 0.079-inch thick. But once I had brought a stock iron up to a high degree of flatness and sharpness, it did an admirable job, too.
Next, I tried out a 2-inch wide iron that works on different common bench planes. Before I could slide it into a #5 jack plane, I had to adjust the iron's support bed, called the frog, back to keep the cutting edge from contacting the plane's mouth. The new iron is about 11% thicker at 0.094 inch versus the original at 0.085 inch, and the extra thickness crowds the mouth of the plane noticeably. To keep shavings from clogging the mouth, I had to raise the cap iron, also called a chip breaker, well away from the cutting edge. This risks leaving a rougher cut, but with the coarser duties of a jack plane, it's not a big deal.
Adjusting the tool so the mouth wouldn't clog took a lot of trial and error, but I found a sweet spot with both #5s. The stiffer iron cut well and powered through the convoluted grain of the apple without any chatter. I then tried the Lee Valley iron in a #4 smoothing plane. I adjusted the cap iron back down toward the cutting edge for a finer cut, and I got good results without as much fuss as the jack plane. Though the mouth was pretty crowded and more prone to clogging , the minimal shavings typically cut with a smoothing plane passed through nicely and provided great results.
Using the Lee Valley iron in a #604 Stanley Bedrock smoother was a bit harder to set up, but once dialed in, it also provided smooth planing with a minimum of clogging and no chatter.
I also tried a replacement iron for older wooden-bodied planes that are used without a cap iron. Lee Valley didn't have the size for my Scottish-made coffin smoother, but their slightly undersized iron cut well. For old planes like this, Lee Valley's replacement irons are a rare resource to put your latest antique store or Internet auction find into service.
The final replacement iron I tried was for spokeshaves. The catalog said it would fit Stanley #51, #52, and more common #151 models from different brands. But out of five of the former models, I could only get it to work in one. The new 0.094-inch thick iron is 52% thicker than my original 0.062-inch version, so it wouldn't fit through the mouth of most of them. The one it fit was left with very little clearance, so it could do only the finest shaving. As for my newer #151, the iron was too wide, and I had to carefully file down both sides with a very thin file to get it to fit. Once in, it had plenty of chip clearance, and it cut more smoothly than the thinner iron it replaced.
Lee Valley replacement plane irons are a quick way to upgrade the cutting edges of your old planes, but their extra thickness may require you to modify how you set up the tool or even the tool itself. For missing or worn out parts, these irons are a must-have, and for saving time and effort in tuning and flattening original irons, they provide a high-quality optional replacement.
Michael Springer is senior editor for Tools of the Trade magazine.
Lee Valley Tools Ltd.
Replacement plane irons