Surface Finish Predictor — Finish Turning Brass
Theoretical Ra and Rt from feed and nose radius for finish turning brass, checked against a Ra 1.6 target.
Brass turns to a near-mirror finish straight off the tool when chips break short, which C360 does naturally. Watch for re-cut chips scratching the surface — air blast matters more than feed tweaking.
Formula
Note: Catalog starting values only — always confirm against your tool maker's data sheet and cut a test part. Machine rigidity, coolant and workholding shift real-world numbers.
Theoretical Ra and Rt from feed and nose radius for finish turning brass, checked against a Ra 1.6 target. A free cnc machining: speeds, feeds & tool wear tool — no sign-up, no upload, instant results in your browser.
About Surface Finish Predictor — Finish Turning Brass
Surface Finish Predictor — Finish Turning Brass computes the governing relationship Ra ≈ f² / (32·rε) · Rt ≈ f² / (8·rε) live as you type. Brass turns to a near-mirror finish straight off the tool when chips break short, which C360 does naturally. Watch for re-cut chips scratching the surface — air blast matters more than feed tweaking. Defaults are pre-filled with realistic values for this exact scenario, and the worked example substitutes your numbers step by step so the math is never a black box.
How to use Surface Finish Predictor — Finish Turning Brass
- 1Enter your values — Feed per rev f, Nose radius rε, Target Ra (sensible defaults are pre-filled).
- 2Read the live results: Theoretical Ra, Theoretical Rt, Max feed for target.
- 3Check the "with your numbers" line to see Ra ≈ f² / (32·rε) · Rt ≈ f² / (8·rε) substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Surface Finish Predictor — Finish Turning Brass?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula Ra ≈ f² / (32·rε) · Rt ≈ f² / (8·rε) with authoritative sources cited on the page (Machinery's Handbook, 31st ed. — Speeds and Feeds; Sandvik Coromant — Milling formulas & definitions)
- ✓Brass turns to a near-mirror finish straight off the tool when chips break short, which C360 does naturally.
- ✓SI ⇄ Imperial toggle converts your inputs in place, so you can work in the units your drawings use
Frequently asked questions
What formula does the surface finish predictor — finish turning brass use?+
It evaluates Ra ≈ f² / (32·rε) · Rt ≈ f² / (8·rε), exactly as published. Sources: Machinery's Handbook, 31st ed. — Speeds and Feeds; Sandvik Coromant — Milling formulas & definitions. The substituted worked example on the page lets you verify every step against the textbook.
How should I read the result — and how far can I trust it?+
Brass turns to a near-mirror finish straight off the tool when chips break short, which C360 does naturally. Catalog starting values only — always confirm against your tool maker's data sheet and cut a test part. Machine rigidity, coolant and workholding shift real-world numbers.
When is this calculator the right tool for the job?+
Theoretical Ra and Rt from feed and nose radius for finish turning brass, checked against a Ra 1.6 target. A free cnc machining: speeds, feeds & tool wear tool. Watch for re-cut chips scratching the surface — air blast matters more than feed tweaking. For neighbouring scenarios, the related tools below cover the same engine with different presets.
Does it support both metric and imperial units?+
Yes — the SI ⇄ Imperial toggle converts the values already in the fields, preserving the physical quantity, so you can flip mid-calculation without re-entering anything.
Related tools
- Surface Finish Predictor — Boring Gray Cast Iron
- Surface Finish Predictor — Hard Turning 60 HRC
- Surface Finish Predictor — Finish Turning Ti-6Al-4V
- Surface Finish Predictor — Facing to Center
- Drilling Speed & Feed — Aluminum 6061
- Drilling Speed & Feed — Mild Steel 1018
- Drilling Speed & Feed — Stainless 304
- Move Time — Camera Station Hop
- Plastic Shrinkage Risk — Fogging System Trigger
Related Manufacturing tools
Spindle Speed Calculator — Aluminum 6061
Carbide starting RPM for milling Aluminum 6061: n = 1000·Vc/(π·D) with a handbook cutting speed preset.
● LiveSpindle Speed Calculator — Mild Steel 1018
Carbide starting RPM for milling Mild Steel 1018: n = 1000·Vc/(π·D) with a handbook cutting speed preset.
● LiveSpindle Speed Calculator — Stainless 304
Carbide starting RPM for milling Stainless 304: n = 1000·Vc/(π·D) with a handbook cutting speed preset.
● Live