YXYSteel information

Steel Plate Machining — Drilling, Milling & Boring

Drilling, tapping and thread milling, face and shoulder milling, rough and fine boring — machined after profiling, on the same datum as the cut edge, so the part reaches your fixture ready to weld.

Φ5–30 mmDrilled holes

0.06 mm/zThread milling feed

8–10%Emulsion concentration

≤0.15 mm/rBoring feed

Why wear plate machines differently

Hardness is only half of it. Abrasion-resistant plate also work-hardens under a dull edge and conducts heat badly, so a drill that survives mild steel will burn up here. Three rules cover most of it: keep the tool sharp, keep the chip leaving the hole, and keep the coolant where the cut is.

The parameters below are the ones we run for NM360–NM500. They are a starting point for quoting; the machine, the holder and the batch all move them.

Drilling

Solid carbide for small diameters, replaceable-blade drills from about Φ20 up. Short, stiff tools out-perform long ones — if the drawing allows a shorter drill, take it.

Section through a drilled hole — illustration; site photo to be supplied.

Recommended drilling parameters — speed (r/min) / feed (mm/min)
Hole	NM360	NM400	NM450	NM500
Φ5 · solid carbide	2500 / 250	2300 / 178	1910 / 152	1592 / 127
Φ10 · solid carbide	1270 / 127	1120 / 90	960 / 75	800 / 64
Φ20 · replaceable blade	1200 / 120	1100 / 90	950 / 75	800 / 65
Φ25 · replaceable blade	950 / 95	900 / 70	750 / 60	640 / 50
Φ30 · replaceable blade	800 / 80	750 / 60	650 / 50	550 / 40

Coolant: 8–10% emulsion, delivered through the tool where possible.

Chip evacuation decides the hole. Once the chip stops leaving, the flutes pack, the torque climbs and the drill breaks — usually on the last hole of a batch. If a hole starts oversized or undersized, check coolant flow and the filter before touching the speed.

Tapping or thread milling

Both work on NM360. Above M15, or from NM400 upward, we thread-mill: the cutter is smaller than the hole, there is no tap to snap in a hardened plate, and the thread can be corrected on the same setup.

Thread milling parameters
Grade	Cutting speed (m/min)	Feed per tooth (mm/z)
NM360	120	0.06
NM400	110	0.06
NM450	90	0.06
NM500	80	0.06

Tapping NM360 with HSS taps runs at about 4 m/min and suits short batches only.

Milling

Face milling for surfaces and steps, shoulder milling for edges and grooves. We mill in climb mode on wear plate: the tooth enters at full chip thickness, which keeps rubbing — and work hardening — to a minimum. Conventional milling is reserved for thin walls where the vibration matters more than tool life.

Face milling — speed (m/min) / feed per tooth (mm/z) / metal removal (cm³/min)
Grade	Speed	Feed	Removal
NM360	100	0.12	≤13.76
NM400	100	0.12	≤13.76
NM450	80	0.12	≤11.46
NM500	80	0.10	≤10.32

Shoulder milling
Grade	Speed	Feed	Removal
NM360	100	0.12	≤3.67
NM400	100	0.12	≤3.67
NM450	80	0.12	≤3.36
NM500	80	0.10	≤3.36

Climb milling versus conventional milling: chip thickness at entry — Climb milling (left) enters at full chip thickness; conventional milling rubs first and work-hardens the surface.

Boring

Rough boring takes the stock out, fine boring sets the size and the surface. Two passes, two tools, one bore that a pin will actually enter.

Boring parameters — speed (m/min) / feed (mm/r) / removal (cm³/min)
Grade	Rough	Fine
NM360	100 / 0.15 / ≤25	120 / 0.08 / ≤1.25
NM400	100 / 0.15 / ≤25	120 / 0.08 / ≤1.21
NM450	90 / 0.15 / ≤21.88	120 / 0.08 / ≤1.33
NM500	80 / 0.15 / ≤21.88	120 / 0.08 / ≤1.33

Rough and fine boring heads with adjustable cutting edges — Rough boring removes the stock, fine boring sets size and surface — two tools, one bore.

Clamping, coolant, and the two things that ruin a hole

Vibration and heat. Vibration comes from overhang and poor clamping — reduce the drill overhang, stiffen the fixture, drop the speed. Heat comes from coolant that never reaches the cutting edge: check flow, clean the filter, clear the coolant holes in the tool.

Parts are measured against the drawing before they leave, and the inspection record travels with the certificate.

Questions we get before the PO

Can you drill through 100 mm wear plate?

Yes, with replaceable-blade drills and a stepped program. Send the hole size and the tolerance band — deep holes are quoted with a pecking cycle.

Do you machine after cutting or before?

After. Profiling first means the hole pattern is drilled from the finished edge, not from a mill edge that gets cut away.

What tolerance can you hold on a bore?

Fine boring is the sizing pass; the band depends on diameter and depth. Give us the fit and we quote the boring allowance with it.

Can one order cover cutting, drilling and welding?

Yes — that is the reason the three sit in one plant. One drawing, one datum, one certificate.

Need a plate solution?

Cut, machined, welded and surface-prepared under one roof in Rizhao.

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