Thread: Correct name for joint system ?

A is a corner half lap

B is a "T" half-lap, and

C is a half blind half lap joint.

Hi

Originally Posted by Groggy

A is a corner half lap

B is a "T" half-lap, and

C is a half blind half lap joint.

Are you SURE about this?

AFAIK they are ALL half-lap joints. C could perhaps be referred to as a blind half-lap joint, but a "HALF BLIND" half-lap joint, I wouldn't think so?

A half-lap joint is a half-lap joint whether it is at the end or in the middle of a piece of timber.

Surely we don't say to woodworkers make a T-half-lap joint when the join is not at the corner of the timber and surely we don't have to specify a CORNER lap joint when the join is at the corner. Specifying a lap-joint or half-lap joint is sufficient?


Maybe terminology has changed since I studied woodwork many years ago.

These joints are also known as halving joints. They are all of the class half-lap or halving. A is a corner half-lap, B is a tee half-lap, C doesn't have a particular name, but I would either call it a tee half-lap, or a blind tee half-lap.

Yes I am sure of this, I have here the textbook that was used for many years in high school woodworking classes: Woodwork In Theory and Practice by John A. Walton. They are also thus named in The Encyclopedia of Furniture Making by Ernest Joyce and The Complete Illustrated Guide to Joinery by Gary Rogowski.

Maybe terminology has changed since I studied woodwork many years ago.

Perhaps what has changed is your recollection, rather than the terminology...

Originally Posted by MrFixIt

Are you SURE about this?

Yes. Reference was the Handbook of Joinery.

Note that 'C' should have read "half blind, half lap joint"

Thanks Guys.. logic prevails!

Thought there might be some obscure, historic term used.

paddy

Alas, Paddy, it is a matter of faith, not logic.

According to the Collins complete WW's manual (1989, pp 218-219), halving joints are NOT lap joints.

As it is commonly the case with definitions, and too $%^&* common with English, it is up to you which prayer book you believe in. (I am agnostic.)

A lap joint is simply overlapping two pieces of material. A halved joint just means there is material removed where they overlap.

Therefore the half lap joint makes perfect sense.

So your prayer book is Wikipedia, Greg? Now, THAT requires a lot of faith!

Surely it is more accurate to say these guys are into a "lap of faith"

Originally Posted by Frank&Earnest

So your prayer book is Wikipedia, Greg? Now, THAT requires a lot of faith!

Oh I dunno. It is possible it is just as accurate as any other book .

I wrote both the half lap and the halved joint articles in Wikipedia, based on Gary Rogowski's book. In his terminology, a halved joint is one in which the joined members are on edge, whereas in a half-lap they are on the flat. This is probably the North American point of view.

In Walton (Australian), halving (not halved) is used interchangeably with half-lap - although it only appears in the headings and 'halving' is used exclusively in the text - this is the Metric update and I wouldn't be surprised if older copies of the book used halving exclusively. Joyce refers to them exclusively as halving joints.

In all cases, the prefixes corner- and tee-, refer to the versions of the joint discussed above (so corner lap-joint/corner halving joint; tee lap-joint/tee halving joint). Rogowski and Walton also refer to a cross half-lap, which is similar to the tee but the intersecting members both carry on past the union in both directions.

Reference:
Woodwork In Theory and Practice by John A. Walton Metric Version. First published 1947, metricated 1974, revised 1979. Australasian Publishing Company
The Encyclopedia of Furniture Making by Ernest Joyce. First publish 1970, revised 1987. Sterling Publishing Co, New York
The Complete Illustrated Guide to Joinery by Gary Rogowski. Published 2002. The Taunton Press

Hi Silent C

Halving is the UK term, Half Lap is the US term as far as I'm aware.

Looks as there's the cross pollination occurring.

Cheers,

eddie

Anybody interested in discussing the sex of angels?

Both The Home Woodworker, Worthington ed., Orbis, London 1982 p.48-56 and the Collins mentioned above use "halving" for joints on the flat and "rebate" or "lap" for joints on the edge. Maybe the Americans reversed this to assert their independence. Which master do we prefer?

Hope none of you is willing to wear a bomb vest and become a martyr for your religious belief...

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