Q1: My parts are 80% round with just a few milled flats and holes. Isn’t a good lathe still the cheapest way?
A: It seems so on the surface, but actually not.
A sliding-head lathe with live tools will outperform any mill on pure cycle time for that kind of work.
But once the part leaves the lathe for those "few" flats and holes, you instantly add two setups, two transport days, and someone else’s profit margin.
We ran the numbers last month on a Ø32 mm 316L pin with six cross-holes and two milled flats:
1. Lathe + separate mill shop: $11.80/pc, 23-day lead time
2. Mill-turn completed in one operation: $9.60/pc, 11-day lead time
The customer directly gave us the next order for 15,000 pieces. Guess which one they picked.
Q2: We’re drowning in rework on aluminum housings. Concentricity keeps failing. What’s actually causing it?
A: Re-clamping after turning.
Aluminum moves when you clamp it twice. Even 0.012 mm is enough to fail a bearing bore check.
One aerospace buyer moved 180 different housings to our 5-axis mill-turn line — rework dropped from 11% to under 0.4% overnight because the part never saw a second fixture.
Q3: My boss only cares about landed cost. How do I prove mill-turn isn’t just "fancy and expensive"?
A: Show him the spreadsheet, not the brochure.
Example from last quarter (real 17-4 stainless valve spool): Traditional route (lathe → mill → grind): $87.40/pc Mill-turn route (one machine): $64.20/pc That single line item saved them $184 000 on a 10k annual program. The machine appears expensive until you consider the cost per part.
Q4: Everyone quotes 6–8 weeks. I need 50 prototype pieces in 10 days. Possible?
A: Yes, but only if the shop doesn’t have to move the part between machines.
We keep three 5-axis mill-turn cells hot 24/7 for exactly this.
Last week: customer sent a STEP file Monday 9 a.m. → finished Inconel 718 manifolds on his dock Thursday 2 p.m.
No expedite fee, no drama.
Q5: Surface finish on grooves is killing us — suppliers blame the material. Who’s right?
A: The supplier who’s still grooving on a lathe with varying chipload is shifting blame.
Mills with constant-engagement trochoidal paths laugh at that problem.
We routinely hit Ra 0.25 on 13-8Mo grooves that other shops call "impossible without polishing".
Q6: We’re sitting on $1.2 M of excess bar stock. Any way out?
A: Stop buying bars for everything. For anything over 30 kg finished weight, we go with forging + 5-axis envelope machining. Real job last month: 220 kg 4140 blank → 48 kg finished gear housing. Waste went from 172 kg to 19 kg. That’s $9 200 saved on one single piece.
Q7: I’m done chasing three different vendors when something goes wrong. Can one factory really do it all in-house?
A: Yes — if they actually own the equipment instead of brokering it.
Here’s what we have under one roof at Simituo right now:
1. 22 Swiss-type lathes for high-volume small turned parts
2. 16 full 5-axis mill-turn machines (up to Ø850 × 3000 mm)
3. Full metrology lab with two Zeiss Prismo CMMs
Your part never leaves the building, and you only ever talk to one person — me.
Ready for shorter lead times, lower scrap, and one phone number that actually picks up?
Send your drawing to www.simituo.com.