Is this 3D model really free?

Yes. There's no account, no watermark and no limit. You can print it, cast it, render it and sell what you make. If you share the file itself, please credit Bling AI with a link to this page.

Which file should I download?

STL for 3D printing or a casting house: the metal only, as one closed solid. 3DM to open in Rhino or Matrix, with the metal and stones on their own layers. OBJ for Blender, KeyShot and most other 3D software. GLB for the web, AR and quick renders, with metal and diamond materials. All of them are in real size.

Is it ready to print and cast?

Yes. The piece is one closed solid (no holes, no overlapping shells) in real millimetres, so it can go straight to castable resin or wax. Ask your caster whether they want it scaled up for shrinkage. Every stone's seat is cut to its exact shape. Prongs are modelled closed over the stones, as they look once set; a setter opens them slightly to drop each stone in.

What size should the side stones be?

A common choice is side stones about two thirds the centre's width (4.5 mm beside 6.5 mm). Closer to the centre size reads as a row of equals; much smaller makes the centre stand out.

Can I make product photos from the model?

Yes. Make product photos of it opens the piece in our 3D viewer: choose the metal and angle, and Bling AI turns that view into studio and on-model photos. That part needs a free account.

Free 3D models · STL · 3DM · OBJ · GLB

Three-stone ring, free 3D model

Q: How much does a three-stone ring weigh?

This one, as first shown, is about 3.2 g in 14k gold, 3.8 g in 18k gold and 5.2 g in platinum, measured from the 3D model itself. The table above has other sizes.

A round centre stone between two smaller ones, each in its own four-prong basket. Choose the ring size and both stone sizes, then download it. Free, with no account.

Building the 3D model…

Ring size

UK L½ · EU 52 · JP 11

Centre stone6.5 mm · about 1.02 ct

Side stones4.5 mm · about 0.34 ct

Band width2.2 mm

Band thickness1.8 mm

Preview in

14k gold: –
18k gold: –
Platinum: –

STL: the metal only, ready for a slicer or a casting house. 3DM opens in Rhino and Matrix with metal and stones on their own layers. OBJ and GLB include the stones. All in real size.

The model

What you're downloading

Stones: a 6.5 mm round brilliant (about 1.02 ct) between two 4.5 mm sides: about 1.68 ct in all.
Settings: three four-prong baskets, turned round the band just far enough that their prongs clear each other.
Band: comfort fit, 2.2 mm wide and 1.8 mm thick at the back, narrowing slightly toward the stones.
Profile: the top of the centre setting sits 6.4 mm above the finger.
Sizes: US 3 to 13 in half sizes, each built to its exact inside diameter (see the ring size converter for UK, EU and JP sizes).
Files: built in your browser when you click, exactly as you set it. STL, 3DM and OBJ are in millimetres (STL and 3DM Z-up); GLB is in metres, as the format requires.

Metal weight

How much does a three-stone ring weigh?

Measured from the 3D model, metal only, with everything else as first shown above. Real pieces vary a little with the alloy and finishing.

Weight by ring size

Ring size	10k gold	14k gold	18k gold	Platinum	Sterling silver
US 4 (14.9 mm)	2.6 g	3.0 g	3.5 g	4.9 g	2.4 g
US 5 (15.7 mm)	2.7 g	3.1 g	3.7 g	5.0 g	2.4 g
US 6 (16.5 mm)	2.8 g	3.2 g	3.8 g	5.2 g	2.5 g
US 7 (17.3 mm)	2.9 g	3.3 g	3.9 g	5.4 g	2.6 g
US 8 (18.1 mm)	3.0 g	3.4 g	4.1 g	5.6 g	2.7 g
US 9 (19.0 mm)	3.1 g	3.5 g	4.2 g	5.8 g	2.8 g
US 10 (19.8 mm)	3.2 g	3.7 g	4.4 g	6.0 g	2.9 g