Measuring and Cutting?

[jander3]

I've seen posts that discuss cutting on mill as 4/4, 5/4 etc.  I believe this is related to how to size the lumber coming off the mill.  I want to search on this topic, excepte I don't know what topic I should be searching. 

I'm interested in understanding cutting properly sized boards on a mill and using the scaling devices to set blade height.

Any reference to threads would be appreciated.

[Magicman]

The quick answer is:  Framing lumber is typically referred to as 2X4, 2X6, etc.  Graded flat lumber is generally measured in ¼ths of an inch thick.  Hence, 4/4 is 1" thick, 5/4 is 1¼" thick, 6/4 is 1½" thick, etc.

[Ron Wenrich]

You will see sizes of lumber as 4/4, 5/4, etc.  Those are nominal thicknesses.  Your 4/4 is the same as a 1", but you want to talk like a lumberman, so you say 4/4.  

But, you won't be cutting it at that thickness.  It all depends on your market.  But, for hardwoods, you will have to cut them thicker to allow for drying and planing.  That piece of 4/4 will make it at 1 1/16", but most guys want it a little thicker.  I cut mine at 1 1/8".

When you get to heavier dimensions, like 8/4, you'll have to take that up to 2 1/4".  

There are several ways to saw your log to get the desired thickness.  I run a circle mill, and all circle mills I have run have stops to advance your headblocks the desired thickness for each thickness of boards you want.  I can't help you out with the bandmill part.

But, when you are going down to a target size, you will have to build a stack.  You take your target size, add a saw kerf and board thickness.  Add a kerf and board for each one you want to take off and add it to the previous one.  

Most guys use a cheat sheet.  For example, if you wanted to get to a 6" target size, and using a combined kerf and board thickness of 1 1/8", then your sets would be at 6", 7 1/8", 8 1/4", 9 3/8", 10 1/2", etc.  

What is the primary type of wood you'll be cutting?  Hardwood or softwood.

I'm sure there will be some bandmillers that will come along and relate their experiences with making cheat sheets.  

[ARKANSAWYER]

Well that is the quick answer for soft woods.  Hardwoods are 4/4 = 1 1/8, 5/4 = 1 3/8, 6/4 = 1 5/8, 8/4 = 2 1/8.
 There are several threads on this and it gets complicated at times.  I have had customers come in and want 4/4 lumber.  When they get here they gripe becasue there is not good ray flake in the boards.  I explain that is becasue they were grade or flat sawn and not quarter sawn.  Then customer will respond "I ordered four quarter lumber and that is what I want!"   :
 My wood Mizer has a scale that can be flipped and has the "quarter" scale on each side, one for hardwoods and the other for softwoods.
 Are we clear as mud yet?

[John Bartley]

There are "standards" for board size, and the previous posters have illustrated this point. However, if you are cutting for non-commercial customers such as home owners or farmers, the easiest way to deal with the "what size do I cut it?" question is to ask your customer what size they want to end up with after the drying and processing is done. If you know that, and you have an idea of the shrinkage factor, then you can "rough cut" to a size that will get your customer to where they want to be. Most homeowners have no idea what a 1/4 scale is, not do they care. All they know (usually) is what they want to finish with.

This (above) doesn't mean that you shouldn't learn the lumber scales and grading standards. It just means that you might not always need to know them. Sometimes it's just easier to speak the language that your customer understands rather then try to teach them yours.

cheers

John

[Magicman]

As you can see, there are many answers to a simple question, and all are correct depending upon who is doing the answering and who is using the lumber.  My answer was the dimensions  for finished lumber.

John Bartley makes a good point about what non-commercial customers want.  I quoted 4/4 to a customer once, and he corrected me very quickly......he wanted it sawed 1".   

[Planman1954]

I may be wrong in chiming in, but that hasn't stopped me before! In the notation 4/4, each number is in reference to 1/4th of an inch, or a quarter inch. So 4 quarters of an inch equals one full inch. So 5/4 would be five quarters of an inch, or one and one quarter inches. So... the 4 is the division of one inch by 4.

Also, I have always assumed that on our bandmills, a one inch cut is only about 1/16th of an inch below a full one inch board after a cut. That allows almost 3/16ths of an inch for drying and planing to reach a surfaced 3/4" board. That's what I shoot for in a finished product. For a 2x type board, I would cut 2" on the mill scale (or 8/4) to allow for a 1 1/2" finished 2x board.

Did you find this article helpful?  :D

[jander3]

Thanks,  I appreciate the feedback.

[sdunston]

Well that is the quick answer for soft woods.  Hardwoods are 4/4 = 1 1/8, 5/4 = 1 3/8, 6/4 = 1 5/8, 8/4 = 2 1/8.
  There are several threads on this and it gets complicated at times.  I have had customers come in and want 4/4 lumber.  When they get here they gripe becasue there is not good ray flake in the boards.  I explain that is becasue they were grade or flat sawn and not quarter sawn.  Then customer will respond "I ordered four quarter lumber and that is what I want!"   :
  My wood Mizer has a scale that can be flipped and has the "quarter" scale on each side, one for hardwoods and the other for softwoods.
  Are we clear as mud yet?

I do the same thing just add an 1/8 for drying, Note I was in the local HOME CHEEPO the oyher day and there 5/4 decking was 7/8.I think we just care about our buyers more ;)
Sam