Straight Taper Rib - 8° Angle

Getting a wall to sit at the same angle on the second pot as it did on the first is the hardest part of throwing a matching set. Eyeballed by hand, a run of ten tumblers ends up as ten slightly different tumblers — and it only shows once they're glazed and lined up on the shelf. This rib takes the guesswork out: the 8° angle is built into the tool, so the wall can only end up where you put the rib.

Rest the flat base on your bat or wheel head, bring the working edge up to the wall, and let the tool do the setting out. The edge is bevelled at 45° on both faces, the two chamfers meeting at a single point, so it contacts the clay along one defined line rather than a broad flat — compressing the wall, truing the profile and clearing slurry and throwing rings as it rises, and leaving a crisp, even surface ready for the rim. Both bevels are identical, so there's no right or wrong face to it.

Use it on the outside to draw a form in as it rises, or on the inside to open one out — the same 8° either way. Off the wheel it does the same job on slab-built and coiled walls, and held against a leather-hard piece it makes a quick gauge to check the taper before you commit to trimming.

Default Sizes:

▶ Micro – 45mm height
▶ Small – 80mm height
▶ Medium – 115mm height
▶ Large – 150mm height
▶ Extra Large – 185mm height

Backing width will vary depending on size. Use the Custom Rib Designer for adjusting heights in 5mm increments from 30mm to 200mm.

Which Angle Do I Need?

Every rib in this family is the same tool at a different angle, so they work as a set — and pots thrown to the same angle stack and nest cleanly when the sizes suit.

▶ 0° – True cylinders: mugs, tumblers, canisters, straight-sided vases
▶ 2° – Barely-there lift: espresso cups and stacking beakers that still read as vertical
▶ 4° – Nesting tumblers, sake cups, small prep bowls
▶ 6° – The classic tapered mug and pint beaker
▶ 8° – Plant pots, utensil crocks, tapered vases
▶ 10° – Production planters and nursery-pot forms with easy stacking clearance
▶ 12° – Wide-mouth bowls, cache pots, tapered lamp bases
▶ 14° – Flared vases, serving bowls, statement planters
▶ 16° – Shallow bowls and wide, open rims
▶ 18° – Maximum flare: wide planters, funnel forms, low serving dishes

Need a Different Shape?

This family covers straight edges from 0° to 18°. If you need something the standard set doesn't do — a wider or narrower backing, a finger hole, a curved or stepped profile — you can draw it yourself in our Custom Rib Designer and we'll print exactly what you draw.

A Note on Wear

These are working tools, and working tools wear. Clay is abrasive — grogged bodies especially — so both the working edge and the flat base will slowly grind down with use. It's gradual, but the base is the part to keep an eye on: once it no longer sits truly flat, the angle it sets stops being reliable, and that's the moment to replace it rather than fight it. Rinsing grit off after every session will buy you considerably longer. Replacing a standard angle takes seconds — and if you're replacing a custom rib, you'll need the design file you saved when you drew it, so keep hold of it.

A Note on Our Photos

The images in this listing are AI-generated rather than studio photographs. The rib itself is shown as a basic silhouette — an outline of the profile, not a picture of the finished tool — and the pots alongside it are visualisations of how a piece might look when thrown with that angle. The silhouette gives you the profile accurately at 115mm high, which is the height shown. If you choose a different height, the image won't change with it — look at the diagram on this page instead to see how your rib will actually look. The tool in your hand will also differ from the image in colour shade, surface finish and small details. The pots are there to show what the angle can do; they're illustrations of what's possible, not photographs of pots we've thrown. We'd rather tell you than have you wonder.

A Note on Performance

We make countless variations of preset rib, and we haven't put every one of them to the test across every clay body and every form — there are simply too many, and potters work in ways we haven't thought of yet. Expect a rib to take a few pots to get the feel of: how the wall ends up depends on how firmly you push, how wet the clay is and how fast the wheel is turning, so give yourself a little practice before you judge it.

If you end up with one that genuinely doesn't work for you, get in touch. We'll refund it, or give you store credit towards a different rib — whichever you'd prefer. That goes for every preset rib we make. The only ones we can't take back are the ribs you draw yourself in the Custom Rib Designer, since those are made to your specs and we can't restock those.

Main Features

☑️ Flat registration base – Sits true on the bat or wheel head so the angle sets itself.
☑️ 45° double-bevelled edge – Both faces chamfered to meet at a single point, contacting the wall on one clean line rather than a broad flat.
☑️ Identical bevels – No right or wrong face; use whichever side falls to hand.
☑️ Broad backing – Something solid to brace your fingers against as you push into the wall.
☑️ Ten angles – 0° to 18° in 2° steps, so you can build up the range you actually throw.