PCB Drill and Via Sizes: Common, Smallest and Extra-Cost Hole Sizes at JLCPCB, PCBWay and OSH Park
What via and drill sizes can you use without paying extra, what is the smallest you can get, and what is it called in mils? Checked against the published limits of JLCPCB, PCBWay and OSH Park, with a checker for your own hole and pad sizes.
Will this hole cost extra?
Try:
1. Via sizes: standard and extra cost
Hole / pad in mm and mil, on a 1.6 mm, 2-layer board. Standard is in the normal price, Extra cost needs a paid option or an advanced order, Not offered is below the published limit. Hover a verdict for the reason. Thinner boards allow smaller holes: JLCPCB's 0.1 mm hole needs a board of 1.0 mm or less, and PCBWay limits 0.2 mm holes to 1.6 mm boards.
| Hole / pad, mmi | Hole / pad, mili | Ring, mmi | JLCPCBi | PCBWayi | OSH Parki | Used for |
|---|---|---|---|---|---|---|
| 0.1 / 0.2 | 3.9 / 7.9 | 0.050 | Not offered | Not offered | Not offered | Laser-style microvia; fan-out under 0.4 mm-pitch BGAs (boards ≤ 1.0 mm) |
| 0.15 / 0.25 | 5.9 / 9.8 | 0.050 | Extra cost | Not offered | Not offered | Smallest mechanical via at JLCPCB; 0.5 mm-pitch BGA fan-out |
| 0.15 / 0.35 | 5.9 / 13.8 | 0.100 | Extra cost | Not offered | Not offered | Via-in-pad for 0.5 mm-pitch BGAs (filled and capped) |
| 0.2 / 0.4 | 7.9 / 15.7 | 0.100 | Extra cost | Extra cost | Not offered | Dense digital boards, 0.65–0.8 mm-pitch BGAs |
| 0.2 / 0.45 | 7.9 / 17.7 | 0.125 | Extra cost | Extra cost | Not offered | Dense routing where 0.3 mm is too big |
| 0.254 / 0.508 | 10 / 20 | 0.127 | Extra cost | Standard | Standard | 10/20 mil, a common CAD default and the smallest OSH Park via |
| 0.3 / 0.45 | 11.8 / 17.7 | 0.075 | Standard | Not offered | Not offered | Smallest via in the JLCPCB standard price |
| 0.3 / 0.6 | 11.8 / 23.6 | 0.150 | Standard | Standard | Standard | The safe default: standard at every board house |
| 0.4 / 0.8 | 15.7 / 31.5 | 0.200 | Standard | Standard | Standard | Power and ground stitching, more current per via |
| 0.5 / 1 | 19.7 / 39.4 | 0.250 | Standard | Standard | Standard | High-current or thermal vias, easy to probe |
2. Plated hole sizes (component leads and pins)
Plated holes have copper on the wall and a pad on both sides, for through-hole leads and pins. The pad here is the hole + 0.6 mm (a 0.3 mm ring), which every board house accepts. Holes are made with real drill bits in 0.05 mm steps, so stick to these sizes (why sizes get rounded). Very large holes are routed (see below). Assumes a 1.6 mm, 2-layer board; hover a verdict for the reason.
| Finished hole, mmi | mil | Pad, mmi | Drilled at, mmi | JLCPCBi | PCBWayi | OSH Parki | Used for |
|---|---|---|---|---|---|---|---|
| 0.20 | 7.9 | 0.80 | 0.30 | Extra cost | Standard | Not offered | Too small for a component lead; costs extra at JLCPCB |
| 0.25 | 9.8 | 0.85 | 0.35 | Extra cost | Standard | Not offered | |
| 0.30 | 11.8 | 0.90 | 0.40 | Standard | Standard | Standard | Smallest plated hole in the JLCPCB standard price |
| 0.40 | 15.7 | 1.00 | 0.50 | Standard | Standard | Standard | Thin wire, test points |
| 0.50 | 19.7 | 1.10 | 0.60 | Standard | Standard | Standard | Test points, 0.3 mm pins |
| 0.60 | 23.6 | 1.20 | 0.70 | Standard | Standard | Standard | 0.4 mm pins, thin wire |
| 0.70 | 27.6 | 1.30 | 0.80 | Standard | Standard | Standard | 0.5 mm round leads |
| 0.80 | 31.5 | 1.40 | 0.90 | Standard | Standard | Standard | ¼ W resistors, 1N4148, DIP ICs, TO-92 |
| 0.90 | 35.4 | 1.50 | 1.00 | Standard | Standard | Standard | |
| 1.00 | 39.4 | 1.60 | 1.10 | Standard | Standard | Standard | 2.54 mm (0.1″) header pins |
| 1.10 | 43.3 | 1.70 | 1.20 | Standard | Standard | Standard | 1N400x rectifiers, ½–1 W resistors |
| 1.20 | 47.2 | 1.80 | 1.30 | Standard | Standard | Standard | TO-220, larger pins |
| 1.30 | 51.2 | 1.90 | 1.40 | Standard | Standard | Standard | Screw terminals |
| 1.50 | 59.1 | 2.10 | 1.60 | Standard | Standard | Standard | Large terminals, DC jacks (check the datasheet) |
| 2.00 | 78.7 | 2.60 | 2.10 | Standard | Standard | Standard | Large pins, power posts |
| 3.20 | 126 | 3.80 | 3.30 | Standard | Standard | Standard | M3 plated mounting hole (ties the screw to ground) |
| 4.30 | 169.3 | 4.90 | 4.40 | Standard | Standard | Standard | M4 plated mounting hole |
| 6.00 | 236.2 | 6.60 | 6.10 | Standard | Standard | Standard | Large plated hole |
| 6.50 | 255.9 | 7.10 | 6.60 | Standard · routed | Extra cost · routed | Standard | Bigger than the largest drill: routed |
| 8.00 | 315 | 8.60 | 8.10 | Standard · routed | Extra cost · routed | Standard · routed | Large plated cutout: routed |
3. Non-plated hole sizes (mounting and locating holes)
Non-plated holes have no copper on the wall, so they are drilled at the size you draw. Use them for screws that must not touch a net, plastic locating pegs, and cutouts. JLCPCB's smallest is 0.50 mm.
| Hole, mmi | mil | JLCPCBi | PCBWayi | OSH Parki | Used for |
|---|---|---|---|---|---|
| 0.30 | 11.8 | Not offered | Standard | Standard | Too small for a non-plated hole at JLCPCB |
| 0.40 | 15.7 | Not offered | Standard | Standard | |
| 0.50 | 19.7 | Standard | Standard | Standard | Smallest non-plated hole at JLCPCB |
| 0.65 | 25.6 | Standard | Standard | Standard | Connector locating pegs (e.g. many USB-C sockets) |
| 1.00 | 39.4 | Standard | Standard | Standard | Plastic locating pegs |
| 1.50 | 59.1 | Standard | Standard | Standard | Locating pegs, alignment pins |
| 2.20 | 86.6 | Standard | Standard | Standard | M2 mounting hole (close fit) |
| 2.70 | 106.3 | Standard | Standard | Standard | M2.5 mounting hole (close fit) |
| 3.20 | 126 | Standard | Standard | Standard | M3 mounting hole (close fit) |
| 3.40 | 133.9 | Standard | Standard | Standard | M3 mounting hole (medium fit) |
| 4.30 | 169.3 | Standard | Standard | Standard | M4 mounting hole (close fit) |
| 5.30 | 208.7 | Standard | Standard | Standard | M5 mounting hole (close fit) |
| 6.40 | 252 | Standard · routed | Extra cost · routed | Standard | M6 mounting hole (close fit): routed at JLCPCB |
| 10.00 | 393.7 | Standard · routed | Extra cost · routed | Standard · routed | Large cutout, cable or light pipe hole: routed |
Screw clearance sizes per ISO 273; see mounting hole sizes for the fit choices and keep-out.
Drill and via limits: JLCPCB vs PCBWay vs OSH Park
As each board house publishes them (read 21 October 2026). Limits change; check the linked capability page before you order.
| JLCPCB | PCBWay | OSH Park | |
|---|---|---|---|
| Smallest hole, standard price | 0.30 mm (12 mil) | 0.20 mm (8 mil) | 0.254 mm (10 mil), 2 & 4 layer 0.203 mm (8 mil), 6 layer |
| Smallest hole, extra cost | 0.15 mm; 0.10 mm on boards ≤ 1.0 mm with ENIG or OSP | 0.15 mm | — (no extra-cost options) |
| Via pad | at least hole + 0.10 mm (hole + 0.15 mm preferred); 0.2–0.25 mm holes with pads under 0.45 mm are part of the small-via option | ring ≥ 5 mil (0.127 mm) standard; 4 then 3 mil at medium / high difficulty | ring ≥ 5 mil (2 layer), ≥ 4 mil (4 & 6 layer) |
| Component (PTH) ring | ≥ 0.18 mm (2 layer), ≥ 0.15 mm (multilayer); 0.25 / 0.20 mm recommended | ≥ 10 mil (0.254 mm) standard; 8 mil medium | as for vias |
| Largest drill | 6.3 mm (larger holes are routed) | 6.0 mm (larger at extra cost; 6.5 mm by milling) | not stated |
| Plated hole tolerance | +0.13 / −0.08 mm | ±0.08 mm | not stated |
| Non-plated holes | 0.50 mm minimum | ±0.05 mm tolerance | not stated |
| Aspect ratio (thickness : hole) | not stated | ≤ 8:1 standard, 8–10:1 advanced; thickest board for a 0.2 mm hole: 1.6 mm | not stated |
| Plated slot, narrowest | 0.50 mm (2 layer), 0.35 mm (multilayer) | 0.50 mm | not stated |
| Non-plated slot, narrowest | 1.0 mm | 0.8 mm | not stated |
| Castellated (half) holes | ≥ 0.5 mm, board ≥ 10 × 10 mm and ≥ 0.6 mm thick | ≥ 0.5 mm (0.4 mm at medium difficulty) | not stated |
| Hole to hole | via 0.2 mm; pad 0.45 mm | vias ≥ 11 mil; component holes ≥ 16 mil | not stated |
| Blind / buried & microvias | HDI laser blind 0.075–0.15 mm; buried 0.15–0.55 mm | HDI offered | not offered |
| Via-in-pad (filled & capped) | 0.15–0.55 mm, default on 6+ layers | offered | not offered |
Seeed Fusion lists a 0.2 mm minimum drill in its standard service. Eurocircuits grades boards by “drill class”, set by the smallest production drill (finished plated hole + 0.10 mm).
Through-hole component hole sizes
Rule of thumb: finished hole = the largest lead diameter (the diagonal for a square pin) + 0.2 to 0.3 mm, and pad = hole + 0.6 mm or more, so the ring is at least 0.3 mm and solders well by hand. Lead sizes vary by maker: these are typical starting points, so check the datasheet.
| Part | Typical lead | Finished hole | Pad |
|---|---|---|---|
| ¼ W resistor, 1N4148, small ceramic or electrolytic capacitor | 0.5–0.6 mm round | 0.8 mm (31 mil) | 1.6 mm |
| DIP IC, TO-92 transistor | 0.46 mm wide flat | 0.8 mm (31 mil) | 1.5–1.6 mm |
| 2.54 mm (0.1″) header pin | 0.64 mm square (0.9 mm diagonal) | 1.0 mm (39 mil) | 1.7 mm |
| 1N400x rectifier, ½–1 W resistor | 0.8–0.9 mm round | 1.0–1.1 mm | 2.0 mm |
| TO-220 | 0.8–1.0 × 0.5 mm flat | 1.1–1.2 mm | 2.0 mm |
| 5 mm screw terminal, larger connector pins | 1.0–1.3 mm | 1.3–1.5 mm | 2.5 mm |
Mounting hole sizes
Clearance holes per ISO 273 (fine, medium, coarse) for metric screws and the usual close / free fit for inch screws. Keep copper and parts outside the screw head (or a washer), plus a margin: the “keep-out” column is the socket-head diameter (ISO 4762) + 0.5 mm.
| Screw | Fine / close | Medium / free | Coarse | Keep-out ⌀ |
|---|---|---|---|---|
| M2 | 2.2 mm | 2.4 mm | 2.6 mm | 4.3 mm |
| M2.5 | 2.7 mm | 2.9 mm | 3.1 mm | 5.0 mm |
| M3 | 3.2 mm | 3.4 mm | 3.6 mm | 6.0 mm |
| M4 | 4.3 mm | 4.5 mm | 4.8 mm | 7.5 mm |
| #4 (0.112″) | 0.116″ (2.95 mm, #32) | 0.1285″ (3.26 mm, #30) | — | ≈ 6 mm |
| #6 (0.138″) | 0.144″ (3.66 mm, #27) | 0.1495″ (3.80 mm, #25) | — | ≈ 7 mm |
A plated mounting hole with a ring ties the screw to that net (often ground); a non-plated one isolates it. Non-plated holes start at 0.5 mm (JLCPCB).
Choosing a Via
- Start at 0.3 / 0.6 mm (12 / 24 mil). It is standard everywhere and plates reliably on any common thickness. It carries roughly 1 A (a common rule of thumb for 1 oz plating). Shrink only where routing needs it.
- Going cheap at JLCPCB: 0.3 / 0.45 mm is the smallest via in the standard price. Anything under 0.3 mm adds a small-via fee to the whole order.
- Fine-pitch BGAs (0.5 mm and below) need 0.15–0.2 mm vias, usually filled and capped so they can sit in the pad. That always costs extra, and often means a 4+ layer board.
- Current: one via is a short, thin copper tube. Use several vias in parallel for power rather than one very large one.
- Tented vias (covered by solder mask) are free and stop solder wicking. Plugged or filled vias cost extra.
Why Does My Drill Size Get Rounded?
Every hole is made by a real drill bit spinning in a CNC machine. The board house keeps a rack of bits in fixed sizes, usually every 0.05 mm: 0.20, 0.25, 0.30 mm and so on. It has no 0.23 mm bit. So when your file asks for 0.23 mm, the machine uses the closest bit it has, 0.25 mm.
Eurocircuits publishes exactly this: every hole is rounded to the nearest 0.05 mm, so it is never more than 0.025 mm off. JLCPCB doesn't publish its list of bits.
Close enough. 0.20, 0.21 and 0.22 mm are made with the same bit, and so are 0.23 and 0.24 mm. And JLCPCB's finished holes can land anywhere from 0.08 mm smaller to 0.13 mm bigger than asked, which is far more than 0.01 mm.
Price limits. At JLCPCB a 0.25 mm hole costs extra and a 0.30 mm hole does not. If you draw sizes that match the drill bits, you always know which side of a limit you are on.
A plated hole gets a thin layer of copper on its wall (drawn thicker here). So the board house drills about 0.10 mm bigger than you asked, and the plating brings the hole back down to your size.
| You draw | Closest bit size | Bit used for a plated hole |
|---|---|---|
| 0.20 mm | 0.20 mm | 0.30 mm |
| 0.21 mm | 0.20 mm | 0.30 mm |
| 0.22 mm | 0.20 mm | 0.30 mm |
| 0.23 mm | 0.25 mm | 0.35 mm |
| 0.24 mm | 0.25 mm | 0.35 mm |
| 0.787 mm (31 mil) | 0.80 mm | 0.90 mm |
Rounding as Eurocircuits publishes it. Other board houses keep their own sets of bits; JLCPCB doesn't publish its list.
Big Holes Get Routed
Every board house has a largest drill bit. A hole bigger than that is routed: a small milling bit moves around the circle, the same way the board outline is cut.
| Board house | Largest drill | Bigger holes |
|---|---|---|
| JLCPCB | 6.3 mm | Routed, no extra cost |
| PCBWay | 6.0 mm | Milled, extra cost (±0.1 mm) |
| OSH Park | about 6.6 mm (unconfirmed) | Milled; draw it as a cutout on the board outline layer |
- Tolerance is looser. A routed hole is less exact than a drilled one. JLCPCB holds routed, non-plated slots to ±0.2 mm. If a bearing or press-fit part needs an exact hole, stay at or under the largest drill.
- Inside corners come out round. The milling bit is round, so slots and cutouts can't have sharp inside corners.
- Draw it the way the board house wants. A large round hole can usually stay in the drill file. Slots and odd shapes go on the board outline (or a mechanical) layer.
Finished Hole vs. Drill Size, and the Annular Ring
Your CAD file gives the finished size. For plated holes the board house drills about 0.10 mm (4 mil) larger, because about 18–25 µm of copper is plated onto the wall. Non-plated holes are drilled at the size you draw.
Holes come out within the tolerance (+0.13 / −0.08 mm at JLCPCB). Set press-fit and tight pin holes with that in mind.
The copper between the hole and the edge of the pad: ring = (pad − hole) ÷ 2. Drill wander and plating eat into it. Too small a ring and the hole can break out of the pad.
The ring is measured from the larger drilled hole, which is why board houses ask for more pad than the finished hole suggests. IPC-2221/2222 set the design rules; the board houses publish their own minimums.
Aspect Ratio and Via Types
Board thickness ÷ hole diameter. Plating has to reach the middle of the hole, so tall thin holes are hard. 8:1 is routine (a 0.2 mm hole in a 1.6 mm board). 10:1 is advanced. Thinner boards allow smaller holes.
- Through via: drilled through the whole board. The only kind on 2-layer boards, and the cheapest.
- Blind via: from an outer layer to an inner layer. Buried via: between inner layers only. Both need sequential lamination (HDI), so they cost extra.
- Microvia: a laser-drilled blind via, about 0.075–0.15 mm.
- Via-in-pad: a via in a component pad, filled and plated over so solder doesn't wick away.
- Tented, plugged, filled: covered by solder mask, partly plugged, or completely filled.
mm and mil
1 mil = 0.001 in = 0.0254 mm.
| mm | 0.15 | 0.20 | 0.254 | 0.30 | 0.40 | 0.45 | 0.50 | 0.60 | 0.80 | 1.00 |
|---|---|---|---|---|---|---|---|---|---|---|
| mil | 6 | 8 | 10 | 12 | 16 | 18 | 20 | 24 | 31 | 39 |
Sources
Board-house limits from JLCPCB PCB capabilities and its help article on extra charges (standard holes ≥ 0.3 mm), PCBWay PCB capabilities, OSH Park services, Seeed Fusion and Eurocircuits drill class, read 21 October 2026. Drill steps, rounding and the +0.10 mm plating allowance from Eurocircuits' drilled holes and finished hole size tolerances guidelines. Clearance holes per ISO 273; socket-head diameters per ISO 4762. Component lead sizes are typical values.