Sine Plate

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Project by Jim Jakosh posted 01-31-2018 09:22 PM 2971 views 13 times favorited 30 comments Add to Favorites Watch

This is a sine plate that was cobbled up from scraps in our shop. I needed to accurately drill some holes at an angle so I quickly made it up and it works good. The pins are exactly 10” apart so to use it, all you do is find the sine of the angle you need to create. Multiply the sine by 10 and cut a shim that thick for under the movable pin and it tilts right to that angle. All the pieces I used were in the scrap barrel ready to go to the dumpster today. There is no finish on it but the two plates have laminate on them . It is made from plywood, particle board, oak dowels and osage orange for the pivot blocks.

Cheers, Jim

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

30 comments so far

View Gene Howe's profile

Gene Howe

12216 posts in 4234 days

#1 posted 01-31-2018 09:30 PM

Now, that’s just plumb cool, jim.
No word on my glass yet.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

View lew's profile


13147 posts in 4561 days

#2 posted 01-31-2018 09:58 PM


I made one of these for drilling chair legs but I never knew why it was called a Sine Plate. Thanks for explaining how to properly use it!

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

View  woodshaver Tony C   's profile

woodshaver Tony C

7567 posts in 4158 days

#3 posted 01-31-2018 10:16 PM

Nice! Never seen one of these before! Thanks for sharing Jim!

-- St Augustine FL, Experience is the sum of our mistakes!

View Joe Lyddon's profile

Joe Lyddon

10923 posts in 4858 days

#4 posted 01-31-2018 10:19 PM


-- Have Fun! Joe Lyddon - Alta Loma, CA USA - Home: ... My Small Gallery:

View tyvekboy's profile


2030 posts in 3819 days

#5 posted 01-31-2018 10:35 PM

Jim -

Great project. Now I’ve got to make one.

Thanks for the lesson.

I’ve never heard of a SINE PLATE and now I know what it is and how it’s used. Now I have another trick in my bag.

Did some research and found some other related info on the internet.



BOOK OF CONSTANTS for Sine Plates—3”, 5” & 10” Sine Plates. Good FREE Downloadable PDF>

Thought this would be interesting for other woodworkers.

-- Tyvekboy -- Marietta, GA ………….. one can never be too organized

View socrbent's profile


1014 posts in 3075 days

#6 posted 01-31-2018 10:48 PM

Wood workers can learn a lot from metal workers. Thanks for the post.

-- socrbent Ohio

View bushmaster's profile


3940 posts in 3088 days

#7 posted 01-31-2018 11:44 PM

interesting again, remember those mathematical table books, now it is all on the calculators

-- Brian - Hazelton, British Columbia

View LittleBlackDuck's profile


4992 posts in 1626 days

#8 posted 02-01-2018 01:01 AM

Thanks for that cool jig JJ.

As a lot have stated… I never knew what a Sine Plate was let alone seen it… Closest I got to it is a dinner plate (and as the missus says… too close, too often)!

-- If your first cut is too short... Take the second cut from the longer end... LBD

View NormG's profile


6506 posts in 3809 days

#9 posted 02-01-2018 01:11 AM

Great jig idea

-- Norman - I never never make a mistake, I just change the design.

View Jimintomahawak's profile


73 posts in 1281 days

#10 posted 02-01-2018 01:22 AM

Very nice. I was in a pinch and needed an accurate angle in the field. I took a hunk of 2×4 and put in 3 deck screws. 2 near the end ¾ from edges and then 5” on center. With the handy smartphone used sine of 22.5×5 to get my angle. A rule of thumb to get close is 1 degree changes elevation 1/64 per inch.

-- Laziness drives creative thinking...

View swirt's profile


5321 posts in 3777 days

#11 posted 02-01-2018 02:39 AM

Thanks for sharing this Jim. I was not familiar with it before now.

-- Galootish log blog,

View woodbutcherbynight's profile


6069 posts in 3214 days

#12 posted 02-01-2018 02:45 AM

Cool jig never knew this was a sine plate buy hey ya learn something new all the time.

-- Live to tell the stories, they sound better that way.

View bondogaposis's profile


5804 posts in 3157 days

#13 posted 02-01-2018 02:51 AM

That is really cool, what are you making with it?

-- Bondo Gaposis

View curt768's profile


5 posts in 923 days

#14 posted 02-01-2018 03:42 AM

Wow that’s a cool project I used to enjoy using those when I was a toolmaker but that was a long time ago never thought of using one for woodworking

View RPhillips's profile


1311 posts in 2641 days

#15 posted 02-01-2018 04:17 AM

awesome, thanks for sharing

-- Rob - Indianapolis IN - Learning... one mistake at a time...

showing 1 through 15 of 30 comments

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