GB 818 Machine Screws: Dimensions, YB 818 and DIN Equivalents
What a GB 818 machine screw is
GB 818 is the Chinese national standard for a cross recessed pan head machine screw: a dome-shaped head that sits on top of the surface, driven by a Phillips-type cross recess. The current edition is GB/T 818-2016, which is technically aligned with ISO 7045 and is widely cross-referenced to DIN 7985. It is the most common fastener in electronics, appliances and instrument assembly, and on this site it is the anchor of the machine screws category.
One thing surprises buyers used to a single “pan head” spec: in the Chinese supply chain the pan head family is split across several standard labels, and the split is not decorative. On our shelves, GB 818 carries the insulating materials while stainless steel lives on a regional standard called YB 818. That mapping is explained below with the actual stock numbers behind it.
GB 818 equivalents: ISO 7045 and DIN 7985
GB/T 818-2016 is dimensionally aligned with ISO 7045. DIN 7985 covers the same cross recessed pan head concept and was superseded by the ISO standard in the German series, so a drawing that calls out any of the three should land you on the same part:
| Chinese | ISO | DIN | Head form |
|---|---|---|---|
| GB/T 818 | ISO 7045 | DIN 7985 (superseded) | Cross recessed pan head |
| GB/T 819.1 | ISO 7046-1 | DIN 965 (superseded) | Cross recessed countersunk, 90° |
For the full 34-family mapping between Chinese, ISO and DIN designations, see the GB / DIN / ISO comparison chart. The countersunk twin of this screw is covered on our GB 819 page.
GB/T 818 dimension chart, M1.6 to M10
These are the nominal (maximum) values from GB/T 818-2016 / ISO 7045. The recess number is the bit: No.0 to No.4 corresponds to a PH0 to PH4 screwdriver.
| Size | Coarse pitch P (mm) | Head dia. dk max (mm) | Head height k max (mm) | Recess No. |
|---|---|---|---|---|
| M1.6 | 0.35 | 3.2 | 1.3 | 0 |
| M2 | 0.40 | 4.0 | 1.6 | 0 |
| M2.5 | 0.45 | 5.0 | 2.1 | 1 |
| M3 | 0.50 | 5.6 | 2.4 | 1 |
| M3.5 | 0.60 | 7.0 | 2.6 | 2 |
| M4 | 0.70 | 8.0 | 3.1 | 2 |
| M5 | 0.80 | 9.5 | 3.7 | 2 |
| M6 | 1.00 | 12.0 | 4.6 | 3 |
| M8 | 1.25 | 16.0 | 6.0 | 4 |
| M10 | 1.50 | 20.0 | 7.5 | 4 |
Note where the table starts: the national standard only defines sizes from M1.6 upward. Anything below that — M1, M1.2, M1.4 — falls outside GB/T 818, which is exactly where the regional standard in the next section earns its keep.
Pitch is the other number on a callout: M3 is 0.5 mm coarse unless stated otherwise, and the coarse and fine options for every size are tabulated in the metric thread pitch chart.
YB 818: the Yuebiao standard that carries stainless below M1.6
YB 818 (粤标, “Yuebiao”) is a Guangdong regional standard for a cross recessed pan head screw, and it dominates the electronics supply chain in southern China. Suppliers list GB/T 818 as its nearest national equivalent, and the thread, drive and general head form match — but supplier drawings show the head itself runs smaller and lower than the national spec:
| Size | GB/T 818 head Ø / height (max) | YB 818 head Ø / height (supplier drawing) |
|---|---|---|
| M2 | 4.0 / 1.6 mm | 3.4 / 1.3 mm |
| M3 | 5.6 / 2.4 mm | 5.6 / 1.9 mm |
Smaller heads matter in practice: they clear adjacent components in dense PCB assemblies and lower the profile under covers. The practical difference to remember is this — the national standard stops at M1.6, while Yuebiao parts are made down to M1, and that is what electronics assemblers actually buy. Our YB 818 standard page lists the stocked range, and the countersunk twin is on the YB 819 page.
How the machine screw shelf actually splits: stock numbers
This is the part no datasheet will tell you, because it is about how one warehouse is organized. Across our 3,684 machine screw part numbers, the standards are not interchangeable slots — each one has taken over a distinct material niche:
| Standard | Part numbers | What it carries here | Materials | Sizes and lengths |
|---|---|---|---|---|
| YB 818 | 572 | Metal pan head, electronics sizes | 304 stainless (274), 1010A carbon steel (186), 316 stainless (112) | M1–M10, 2–200 mm |
| GB 818 | 299 | Insulating and soft pan head | PA66 nylon (164), H62 brass (68), clear polycarbonate (67) | M2–M8, 3–100 mm |
| GB 819 | 226 | Insulating countersunk | PA66 nylon (115), H68 brass (64), clear polycarbonate (47) | M2–M8, 4–60 mm |
| DIN 967 | 272 | Pan head with captive washer | 1010A carbon steel (112), 304 stainless (80), 316 stainless (40) | M1.4–M8, 3–60 mm |
Three conclusions fall straight out of that table:
- Need a metal pan head below M1.6? GB/T 818 does not define it; order YB 818. The stainless Yuebiao range runs from M1 (16 part numbers, listed as both “M1” and “M1.0”) through M3 (85) and up to M10 (14).
- Need a pan head that does not conduct or short a board? That is the GB 818 slot on our shelf: PA66 nylon, brass or polycarbonate from M2 to M8. Metal-obsessed buyers often search stainless here and find plastic — the material is the point, not an omission.
- Need a washer that never falls off? DIN 967’s captive conical washer saves the assembly step, and on our site it carries the carbon steel and stainless range from M1.4. See the DIN 967 page for the stocked matrix.
Sizes below M1 are a different discipline again; the micro screws guide maps every stocked length from M0.9 up.
Drive types: cross recess, PH bits and slot depth
Every GB 818 / YB 818 part on this site uses the H-type cross recess, driven by standard Phillips (PH) bits. The recess number scales with head size, so a No.0 bit fits M1.6–M2, a No.1 fits M2.5–M3, No.2 fits M3.5–M5, and so on per the table above. Two purchasing notes that save rework:
- The recess is specified by penetration depth, not bit size alone. A worn or wrong-number bit cams out and rounds the recess — the classic failure in automated assembly lines.
- Because YB 818 heads are lower than the national spec, recess depth on small Yuebiao parts is shallower too. Torque control matters more, not less, on the cheap screws.
Slotted legacy heads: GB 65, GB 67 and GB 68
Before cross recess took over, pan and countersunk screws were slotted, and the old national designations still circulate: GB/T 65 (slotted cheese head, DIN 84 / ISO 1207), GB/T 67 (slotted pan head, ISO 1580) and GB/T 68 (slotted countersunk). We still stock 128, 148 and 105 part numbers under those labels respectively. Slotted heads survive in service and repair work for honest reasons: a flat blade is everywhere, slot depth cannot cam out the way a worn Phillips does, and torque is naturally limited. But they carry far less torque without slipping and are slower on automated lines, so for new designs the cross recessed GB 818 / YB 818 range above is the default choice.
Materials and grades on the shelf
The metal range is dominated by 304 stainless (1,909 part numbers across the whole machine screw category), with 316 stainless at 336 for chloride-heavy environments and 1010A carbon steel at 770 for cost-sensitive, plated builds. Grade designations and what A2-70 actually means relative to steel grade 8.8 are compared in A2-70 vs grade 8.8. One caution for assembly: stainless against stainless threads galls if you run it dry; the fixes are in our galling guide.
Ordering: no minimum, priced per piece
Every machine screw here is priced per piece in USD with no minimum order, dispatched from our own warehouse within 24–48 hours. Prototypes need 40 pieces, not 40,000 — the shelf is priced for that. For the countersunk layout version of the same head, start from GB 819; for the socket-head alternative when torque is high, the DIN 912 size chart is the reference.
FAQ
What is the difference between GB 818 and YB 818?
GB/T 818 is the Chinese national standard for cross recessed pan head screws, defined from M1.6 to M10. YB 818 is a Guangdong regional standard (“Yuebiao”) for the same head form; suppliers list GB/T 818 as its nearest equivalent, but its heads run smaller and lower per supplier drawings, and it is produced down to M1 — below the national standard’s floor.
What is the DIN equivalent of GB 818?
ISO 7045 is the dimensional equivalent; DIN 7985 covered the same screw and was superseded by the ISO standard. GB/T 818-2016 is aligned with ISO 7045, so drawings calling out GB 818, ISO 7045 or DIN 7985 refer to the same part.
Is GB 818 the same as a Phillips screw?
It uses the H-type cross recess, which is driven by standard Phillips (PH) bits — No.0 through No.4 matching PH0 through PH4. The recess is specified by penetration depth, so the numbers scale with head size rather than being a fixed bit size.
What sizes does YB 818 cover that GB/T 818 does not?
M1, M1.2 and M1.4. The national standard stops at M1.6, but electronics assembly lives below that, which is why the regional Yuebiao standard dominates small sizes. We stock 572 YB 818 part numbers from M1 to M10 in 304 stainless, 316 stainless and 1010A carbon steel.
Are GB 818 nylon screws conductive?
No. PA66 nylon and polycarbonate are insulating, and brass is conductive but non-magnetic and soft — on our shelf the GB 818 label is where all three live, from M2 to M8. That is why metal-range buyers see plastic under GB 818 here.
Why do YB 818 heads look smaller than my old samples?
Because they are. Supplier drawings show an M2 Yuebiao head at 3.4 mm diameter and 1.3 mm height against the national maximum of 4.0 / 1.6 mm, and M3 at 1.9 mm height against 2.4 mm. If your assembly clearance was measured on a national-spec sample, verify the swap on a fixture first.
Do you stock GB 819 countersunk and DIN 967 washer-head variants?
Yes — 226 GB 819 countersunk part numbers (PA66, H68 brass, polycarbonate) and 272 DIN 967 captive-washer pan heads (1010A carbon steel, 304 and 316 stainless), all priced per piece with no minimum order.