Reaming Pivot Holes

Peter Atwood

Peter Atwood

Joined
Oct 26, 2000
Messages
2,468
I am a complete novice here so bear with me. What I want to know is how exactly does one ream a pivot hole? I have some 3/16 pivot pins and I am planning on getting a 3/16 reamer. I understand that what I want to do is drill an undersize hole and then ream it to 3/16 but what I don't understand is why this will be more precise than just drilling it out. Isn't the reamer just a drill bit? Can I use my Delta drill press for this? I have it set now on the slowest speed which is about 600.

Also, what is "lapping" and how is it done?

TIA,



------------------
Peter Atwood

email:fountainman@hotmail.com
 
When you get the ream you'll understand the difference. A drill bit has two cutting edges . A ream has 6 cutting edges therefore you get a smoother more precise hole. Your drill press is fine, just make sure it's all squared up. If you don't have a dial indicator, heres a trick Tom Mayo shared. Bend a piece of wire into a large Z. Chuck one end in the press and raise the table till the other end of the wire almost touches.It helps to tape a piece of white paper to the table and bad some ink on the end of the wire. Then turn the chuck by hand to see if the wire hits the table anywhere. I did this and found my drill press was squared up side to side but about 1/32" off front to back.
Lapping is simply rolling some fine grit sand paper around something small enough to insert into the pivot hole. You can spin it in your fingers to clean the pivot up after heat treat. Hope this helps!

------------------
Take care!! Michael

Always think of your fellow knife makers as partners in the search for the perfect blade, not as people trying to compete with you and your work!
http://www.nebsnow.com/L6steel
Buzzards gotta eat, same as worms!!!
 

Straight reamers are fine for relatively thin materials. Left and right hand spiral reamers are designed to either pull the chips up or push them down and really don't have too much advantage with thin knife materials.

If you're using a high speed drill press, I'd recommend using carbide reamers beacuse they can take the heat better than high speed or cobalt reamers.

Also, there are special tools called "laps" that use abrasive compound to polish hole diameters. Then, there are "hones" which use abrasive sections to achieve diameter and finish.

Using a piece of sandpaper in a slotted rod doesn't match either tools' performance, but is good enough for many applications where you're just removing heat treat dirt. I have also used spiral wire brushes to remove this film in certain applications.

------------------

Tom Anderson
Hand Crafted Knives

[This message has been edited by Tom Anderson (edited 02-15-2001).]
 
You must log in or register to reply here.
Back
Top