How do I dimension a non-45° chamfer or bevel on a drawing?

Give the angle plus one linear dimension — either depth or width — for example '30° × 2 mm deep'. For 45° chamfers the short notation C1 (leg length) is standard because width and depth are equal. For other angles the two legs differ, so a single 'C' callout is ambiguous and shops will query it. State datum faces too, since width measured on each leg differs for non-45° angles.

Chamfer vs Fillet vs Bevel: Three Edge Geometries, Clearly Separated

Q: Is a bevel just a chamfer with a different name?

Not quite. In drawing practice a chamfer is a small edge treatment on a corner — usually 45°, called out as C-size — whose job is edge relief or assembly lead-in. A bevel is an angled face treated as a feature in its own right: it can run the full thickness or width of a part (a bevelled plate edge, a bevel gear tooth), it often carries a non-45° angle with its own tolerance, and it may serve alignment or mating functions rather than edge breaking. Every chamfer is geometrically a bevel, but not every bevel is called or treated as a chamfer.

Q: Which of the three is easiest to inspect?

Chamfers: two CMM points or an optical gauge give angle and width directly. Bevels need angle plus a located dimension, so a few more probing points. Fillets are the most involved — radius gauges and optical projection for small radii, CMM scanning for functional ones. All dimensioned edge features on production orders at Boyang Hardware are covered by the 100% pre-shipment inspection and dimensional report.

Definitions, callouts and machining notes · Boyang Hardware, Zhongshan, China

Direct answer All three are edge or transition treatments, and they differ by geometry and by role. A chamfer is a small angled flat cutting a corner — conventionally 45°, noted C-size — used for edge relief and assembly lead-in. A fillet is a concave or convex rounded transition that spreads stress and rounds corners. A bevel is an angled face treated as a feature in its own right, often full-width or full-thickness and often at a non-45° angle with its own tolerance. Quick test: small + on a corner + 45° → chamfer; rounded → fillet; large angled face or non-45° functional angle → bevel.

45°default chamfer angle
C1 notation1 mm leg, 45°
3/4/5-axismilling covers all three
100%inspection before shipment

Side-by-side comparison

Table 1 — The three edge treatments compared as we read them on customer drawings.
Property	Chamfer	Fillet	Bevel
Geometry	Straight angled flat at a corner	Circular-arc rounded transition	Angled face, any scale
Typical angle	45° (sometimes 30°/60°)	Radius, not angle	Any specified angle, often 30–60°
Drawing callout	C0.5, C1 × 45°	R1.0, R2 +0.5/0	30° × 2 mm deep, or dimensioned face
Primary job	Edge break, fastener lead-in, seal protection	Stress reduction, corner softening, flow	Alignment, mating angle, structural edge (weld prep), cosmetic taper
Scale	Small (0.2–2 mm typical)	Small to structural (R0.5 up)	Can run full thickness/width
Machining cost	Lowest	Moderate (tool radius dictates)	Depends on size; large bevels are real milling work
Typical tolerance	General block, or ±0.1 mm if dimensioned	Profile / plus-range on radius	Angle ±0.5° typical, ±0.1° if functional

For a deeper dive into the chamfer-vs-fillet trade-off alone, see chamfer vs fillet for machined parts; for radius sizing rules, see the fillet engineering guide.

Geometry formulas and callouts

For a 45° chamfer the callout C1 means both legs are 1 mm; width = depth, and the chamfer face length is width × √2. For any other angle, with depth d and half-angle θ from the face:

width = d / tan(θ) · chamfer face = d / sin(θ)

That asymmetry is exactly why non-45° callouts must state which leg is dimensioned — "2 mm deep" and "2 mm wide" produce different cones on the same C1-style bore chamfer. Bevel angles are usually toleranced in degrees (±0.5° is common) because a small angular error over a wide bevel becomes a large linear error at the far edge.

How each is machined

Chamfers: spot drill or chamfer mill, single pass, in-cycle. Bore entry chamfers are cut in the same set-up as the bore to keep concentricity.
Fillets: corner-radius end mill matching the radius; internal corners bounded by tool access, with wire EDM (7 machines on site) as the fallback for sharper transitions.
Bevels: angled contouring — 3-axis with a tilted cutter for small bevels, 4/5-axis set-ups for full-face angles. Large structural bevels (weld prep on plates) are machined as genuine features with their own datum and inspection.

All of this is routine across our 54 machine tools in aluminium (including 7075), brass, stainless steel, titanium and copper — see 7075 machining and titanium parts.

When a bevel is the right answer

Choose a bevel when the angle itself does work: alignment tapers that centre one part into another, wedges and clamping faces, bevel-gear-adjacent geometry, weld preparation where the angle is set by the welding procedure, and appearance tapers on enclosures. If the edge only needs to stop being sharp, do not spend a bevel on it — a C0.5 chamfer does the job at a fraction of the machining and inspection effort. And if the real question is rounded corner versus angled corner on a cosmetic face, that comparison lives in round vs fillet corners.

Honest limits: terminology varies by industry and country — some sectors say "bevel" for what drawings elsewhere call a chamfer, and welding codes have their own definitions. We machine to what your drawing dimensions, not to the word in the title block, which is why ambiguous callouts (a "C2" with no angle on a non-45° intent, or a bevel with only one leg dimensioned) get queried during quotation rather than guessed. Tolerance values in Table 1 are production-typical, not guarantees for every drawing; critical edge features are confirmed at quotation, which takes 1–2 working days.

FAQs

Is a bevel just a chamfer with a different name?

No — a chamfer is a small corner relief, usually 45° and C-callout; a bevel is an angled face as a feature, often full-width, often non-45°, with its own function and tolerance. Every chamfer is a small bevel; few bevels are chamfers.

How do I dimension a non-45° chamfer or bevel?

State the angle plus one linear dimension with the reference face, e.g. "30° × 2 mm deep". Single-letter C callouts are only unambiguous at 45°.

Which of the three is easiest to inspect?

Chamfers (two-point angle/width check), then bevels (angle plus located dimension), then fillets (gauges, projection or CMM scanning). Dimensioned edge features are covered by our 100% pre-shipment inspection.