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HHIP 3900-3212 3 Jaw Chuck 1-1/2-8 Threaded Backplate, 4"

  • Based on 135 reviews
Condition: New
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Availability: In Stock.
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Arrives Sunday, Nov 24
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Size: 4" Size, 1 1/2"-8 Thread


Style: For 3-Jaw Chucks


Features

  • Must be machined for concentricity
  • Model Number: 3900-3212
  • Item Package Dimension: 3.0" L x 6.0" W x 3.0" H
  • Item Package Weight: 2.6 lb

Description

4" 1-1/2" 8 Threaded 3-Jaw Backplate Assembly instructions included. D is 4". D2 is 10 2.90". Bolt circle is 3.3". Number of bolt holes is 3.


Product Dimensions ‏ : ‎ 3 x 1 x 6 inches; 2.29 Pounds


Item model number ‏ : ‎ 3900-3212


Date First Available ‏ : ‎ July 11, 2013


Manufacturer ‏ : ‎ HHIP


Country of Origin ‏ : ‎ China


Best Sellers Rank: #371,251 in Tools & Home Improvement (See Top 100 in Tools & Home Improvement) #310 in Power Lathe Accessories


#310 in Power Lathe Accessories:


Customer Reviews: 4.3 4.3 out of 5 stars 135 ratings


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If you place your order now, the estimated arrival date for this product is: Sunday, Nov 24

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Top Amazon Reviews


  • A little wobbly
Size: 4" Size, 1 1/2"-8 Thread Style: For 3-Jaw Chucks
Installed it and it was out of round about .030". Had to cut the face to get it true. Then had to cut it to fit the chuck that this page recommended. It may have gotten damaged in shipping. There was a ding on it from being dropped or something. It does thread on and the bolts worked with the chuck. I'd buy it again if I needed to. ... show more
Reviewed in the United States on February 11, 2023 by Customer

  • double check adaptability
Size: 3" Size, 1"-8 Thread Style: For 3-Jaw Chucks
this 8x1 adapter is functional. however i would ensure the "tenon" on this that aligns to the back of your chuck are correctly sized. this was the recommended plate for my chuck and while the holes aligned it did not seat causing a misalignment out of center and in the regards of a chuck that's not acceptable. after a hour of creating spacers and making sure everything lined up correctly it works as described! ... show more
Reviewed in the United States on March 28, 2023 by Chance

  • Had to be machined to fit. Amazon recommended fit was wrong.
Size: 4" Size, 1"-8 Thread Style: For 3-Jaw Chucks
The raised ring on the front of this adapter appears to be a nonstandard size. I had to machine about 1.5mm off it, decreasing the diameter about 3mm for it to fit the 4" lathe chuck I bought with it. Since I could not use the lathe chuck to machine this I had to do it by hand with an angle grinder, but it all turned out okay. Note, the 4" lathe chuck I bought with this is the one Amazon said would fit this adapter, recommending they are "often purchased together." ... show more
Reviewed in the United States on February 23, 2023 by Steven Michaelis Steven Michaelis

  • Item worked as expected
Size: 3" Size, 1"-10 Thread Style: For 3-Jaw Chucks
The mounting plate worked out perfectly for my 3 jaw Chuck. The threads fit my lathe spindle very nicely.
Reviewed in the United States on February 12, 2023 by Janice A. Piunno

  • Almost there but not quite.
Size: 3" Size, 3/4"-16 Thread Style: For 3-Jaw Chucks
I bought this baseplate so that I could mount an ER-32 collet chuck ( HHIP 3901-5032 ER-32 Collet Chuck, 80 mm Diameter ) by the same manufacturer to the spindles on both my Sherline lathe and mill. I was hoping that it would mate right to the chuck but it doesn't quite do that. That's partly why I only gave it three stars. The chuck looks like it is made of quality stainless steel. But this backplate looks like it is made from a lower quality steel that will rust. It didn't come as blue and shiny as the one in the photograph but it will shine up a little after doing some cutting I plan to do to make the two parts fit together. Luckily, the three machine screw holes align correctly so both will work with the bag of M6 hex bolts that I bought. The insert on the large end of the backplate is 76.6mm in diameter while the recess on the back of the chuck is only 74.6mm in diameter. I will have to cut the insert down in order for it to fit into the recess on the back side of the chuck. One could bore the recess of the chuck larger but it would remove material supporting the threaded holes in the chuck. But before I do this operation, a facing operation on the small end of the backplate needs to be done first. The 3/4-16 spindle threads do fit my machine's spindle but they don't go all of the way through the backplate. Also, they look pretty rough (with little burrs on them) but the device seems to mount okay. Taking off 5 or 6mm of metal off the small end of the backplate will bring the threads closer to the outer surface so that the threads on the spindle will have more to grab on to. I am hoping that the backplate is easy to machine because all of my lathe cutting tools are made of HSS. To do this facing operation, I will mount the backplate backwards onto the spindle and the backplate will become my work piece. After that machine operation is done I can turn the backplate around and mount it as it will when the chuck is bolted onto it. Turning the insert down by about 1mm will reduce its diameter and the chuck should be able to fit around it. The bolts are not for alignment but will just hold the two pieces together. If the backplate inserts snuggly then it will serve to hold the chuck precisely in position relative to the backplate and thus the lathe itself and its tooling. This will be the most critical part of the operation and I will need to check for fit between successive passes so that I don't overcut the insert. If the backplate had come to already fit the chuck then I would have given this product four stars. If it had also been made of stainless steel, then my review would have given it five stars. We'll see how the machine operation goes. -----------------------Later I did all of the machining operations and it was a success. I cut about 6mm off the small end and this exposed the 3/4-16 threads. This left some burs on the surface so that when I mounted it, the thing wobbled. Luckily I didn't panic. After eliminating the burs with a slight boring operation, the wobble went away and it was visibly very steady. One thing to note is that the insert on the large end has a slight taper as does the collet chuck that I bought this thing to mount. But I don't think the taper does much on such a short little insert which only protrudes about 3mm. But this is enough to register the chuck solidly. I made 0.01mm cuts the whole way because I feared making the insert to small in diameter which would ruin the backplate. I was testing for fit after each pass near the end. After the final pass the insert dropped in and I was done. I know I voided the warranty on this thing but now it is usable. Oh happy day! I can finally use 3/8" and larger end mill bits on my mill and I can mount round stock up to 20mm in diameter on my lathe without having to resort to the 3-jaw chuck. ... show more
Reviewed in the United States on February 4, 2017 by Paul K. Mckneely

  • Works fine for the price
Size: 4" Size, 1 1/2"-8 Thread Style: For 3-Jaw Chucks
I’m not a professional working with lathes is out of balance a few .000 of an inch but for my jobs is okay I use for hobby some work for me and learn to use the lathe so I’m good with it
Reviewed in the United States on October 10, 2022 by Manolo

  • Needs to be turned down to fit
Size: 3" Size, 3/4"-16 Thread Style: For 3-Jaw Chucks
I bought this to go on my new accusize 3 inch 3 jaw chuck. The bolt pattern was correct but I had to turn down the mating surface to fit the chuck. I guess that’s how you get a precise fit. Would have been nice to know up front.
Reviewed in the United States on February 3, 2022 by tony burometto

  • It worked
Size: 4" Size, 1"-10 Thread Style: For 3-Jaw Chucks
Fits well, bolted my chuck to it without any modification
Reviewed in the United States on June 8, 2022 by Amazon Customer

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