Blade Centering

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There are a number of reasons why a razor closes off center. This article is going to discuss why this occurs along with some options for correcting and centering an unaligned blade.

Occurrence[edit | edit source]

If your blade is closing off center don't panic, this is not uncommon when restoring straight razors. Many razor brands (old and new) are sometimes off center when shipped from the factory. The following are post from SRP forum members that will confirm that you are not the only one that has run into a blade closing off center...

"Very common. I think ALL the pre-1900 or so razors I've worked with (certainly all Sheffield...seems to be some variability in the Solingen) have been this way. They need the tang to taper, in it is MUCH easier to do without messing up to grind or forge ONE side. A lot of old horn scales are not perfectly symmetrical to make up for this... just drop an extra bearing (thrust washer) on the ground side and you'll be golden." ~BKratchmer
"You know, a lot of my vintage razors (mostly 1850-1875 sheffield) are only parallel to the tang on one side, and the other side is angled away at anywhere from 5 to 15 degrees." ~hoglahoo
"On the old razors it seems that one side was grinded with a taper and the other was not. On the DAs it appears pretty random, and is most like a result of the way they were cast/banged out." ~Seraphim

General Causes[edit | edit source]

There are a number of causes for off center blades, besides the blade construction being off center; scale construction, pins, and uneven wedges can all contribute to an off center blade. Here is another post from an SRP Forum member on this very issue (some lines removed for context)...

"There are several factors that go into getting the blade to close straight... First is the tang straight??? I struggled with this one myself for a while thinking I had messed up when I built the scales and made them uneven.. Finally I checked the tang itself and the light came on, ALL TANGS ARE NOT STRAIGHT... Hold the tang against a known flat surface and see if there is deflection.... Second are the scales straight???? ... Third is the pin bent??? ... Fourth are the scales uneven??? ..." ~gssixgun

Cause Discovery[edit | edit source]

In order to know how to fix your specific alignment issue you will have to discover what is causing the issue. Start by finding out if the blade is warped, twisted, or ground uneven. To do this simply place the unpinned blade on a flat surface and press down on the pivot hole. Do this for both sides of the blade to get an accurate view of the issue. After inspecting the blade from all sides you will probably have a good idea if the blade is straight, and if not, why it is off.

If you are working with a straight razor that you want to avoid unpinning, attempt the pin adjustment listed below before unpinning and attempting the flat surface test.

The following are example pictures of a flat surface test...

Sample 1 Check1.jpg
Sample 2 Check2.jpg
Sample 3 Check3.jpg

Notice "sample 1" the blade is clearly curved where the tang meets the blade and "sample 3" is either unevenly ground or twisted as you can see the edge of the blade at the toe is higher than the spine of the blade.

In the following sections we will discuss fixes for different alignment issues.

Pin Adjustment[edit | edit source]

If you want to avoid unpinning your razor or you feel the alignment is only slightly off. Some issues can be corrected by doing a minor Pin Adjustment. This adjustment is simply holding the razor over a hard surface and using a tablespoon or peening hammer, striking the pivot pin in order to cause the scale to adjustment away from the scale it is contacting (This method can also be used tighten up a loose scale).

You don't need to strike the pin very hard, you do not want to risk bending the pin or accidentally hitting/damaging the scales. A good test for how hard to hit the pin, is to hit it no harder then you would your finger... Seriously put you finger out on the anvil and tap the spot right at the cuticle and fingernail that real sensitive spot... If it hurts your finger you are tapping to hard...

Scale Adjustment[edit | edit source]

If the blade appears not to be straight after performing the flat surface test, then the issue may be compensated for in your scale construction or by modifying your existing scales.Due to the fact that scale construction and shape vary widely. You will have to discover based on your own scales where the issue lies, verify that each scale and your wedge is straight and even.

If the blade did not appear straight after performing the flat surface test, then adjusting the scales to compensate for the issue is an option. For scales made out of a plastic material you can try heating and bending the scales to suit the blades needs (this will be covered below in a section about "Heating" to correct alignment). Another option is removing some material to adjust the alignment, this technique is described in a post from SRP Forum member "spazola"...

"My thoughts on centering are that the pivot pin has little to with it. I have had little luck trying to peen one side or the other to get the blade to move to where it needs to be. I have had good luck by changing the inside surfaces of the scales to compensate for poorly shaped blades. I think that the blades centering is regulated by how the tang rubs against the inside surfaces of the scales. A little material removal down by the pivot end makes for a big change on the wedge end. The wedge pin also plays a role in the centering, If you re-pin the wedge end it gives you a chance to slide the two scales back and forth thus changing their position relative to the blade. The blade was too far south. The bulk of the material was removed from the north side, allowing the tang to move a little further to the north. An emery board works well for this. A folded paper towel works well for applying finish to the inside surfaces.
This works great on wood scales, but I have also done it on factory made non-wood scales." ~spazola


Spacer Washers[edit | edit source]

Perhaps the easiest method for giving yourself clearance from the scale is to simply add another spacer washer to the side with the issue. This will give you some extra clearance to avoid the scale. If you don't care for the look of an additional spacer washer on one side or the extra washer is just not enough to comfortably clear the scale. You can file a spacer washer into a wedge shape to adjust for the twist or uneven grind then affix it to the tang. This adjustment will ensure the surface is corrected whether the blade is opened or closed as it should flatten out the surface on the tang the the scale is contacting. The following diagram will illustrate the basic concept of this method if it is not already clear...


The thicker portion of the washer should positioned to compensate for a low part in the tang.

Vise Adjustment[edit | edit source]

One method for straightening a curved tang is to place the tang in a vise along with some strategically placed pins, then using slow pressure from the vise to force the tang alignment. The Pins will be placed in the vise with the tang so there is one pin on the peak of the curve and 2 pins on the opposite side, spaced to allow the single pin to act as a fulcrum when pressure is applied. The following diagram will illustrate the basic concept of this method if it is not already clear...


This technique should be performed on the tang (not the spine) of the razor, as confirmed by the following post from an SRP forum member...

Yes, I straightened the tang, not the spine. As Glen's original post shows, the tangs are often out of alignment. I have never found the spines of any of them to be warped/bent. ~Seraphim

Heating Adjustment[edit | edit source]

Heating with steam or boiling water can be used to make adjustments to correct for misaligned blades is another option. Cautioned should be exercised when using heat as an adjustment tool to ensure you don't burn yourself, melt your scales, or damage your blades temper. This method is similar to another article already listed in the Wiki regarding straightening warped scales. This method is described the the following posts by SRP forum members...

"Also to straighten slightly warped scales or get around problems with the blade sitting off center, I fill a coffee cup with boiling water from the kettle, place the offending end of the razor in it whilst applying a slight twist as needed, you will feel it go, lift it out and just hold it under tension for a few seconds until you feel it relax, Bingo! Its worth a go, esp if you don't need to descale or re-pin. Hope this helps and good luck with your endeavours once again" ~tat2Ralfy
"Plastic scales can be bent to fit over the spout of a kettle of boiling water. Not the most elegant solution but not too noticeable if the bend is slight,and of course bent ones can be straightened in the same way. Bend them to where you want them then run under cold water." ~Stropper

See also Fixing warped scales for an example of how to get scales perfectly straight using steam/boiling water and a Jig.

Hammer Adjustment[edit | edit source]

Hammering a blade to adjust it back into shape runs such a high risk of breaking the blade that it will not be covered in this article. You can assume if you need to read this article for help with blade alignment then you are probably lacking the experience required to take a hammer to your blade.