Tel：
+86 13143444311
Email：sst@szsst88.com
Fax：+0086-755-27322278
Address：Building 9, First Industrial Zone, Tantou Industrial City, Songgang Street, Baoan District, Shenzhen 518105, Guangdong, China
Type:Tapping Screw, Pan Head, Combination Recess (Phillips + Slot), Full Thread (Non-Standard)
Materials:Carbon Steel
Surface treatment:Blue Zinc Plated (blue-white, bright)
Head Type:Pan Head (low dome just under half the head diameter in height, flat bearing face, small fillet into the shank)
Drive type:Combination recess — Phillips cross (four tapered wings, pointed centre) plus one straight slot across the full head diameter
Thread:Coarse single-lead self-tapping thread, rolled, full thread up to the bearing face
Point:Sharp tapered gimlet point; no cutting flute, no drill point
Process:Single-die heading, slotting, thread rolling, blue-white zinc plating, sorting
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Number:818
We manufacture tapping screws with a pan head and a full-length coarse thread, in carbon steel with a blue-white zinc finish and a combination cross-and-slot recess, quoted from M1 to M14. Thread length, point, head and drive are taken from your drawing.
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ISO 9001:2015 · Manufacturing since 1998 · 8,678+ customers · 89 countries and regions
Made to order – there is no stock catalogue. Each part is produced to your drawing, and production starts after drawing review and first-article approval.
A tapping screw with a pan head is a self-tapping screw with a low domed head, a flat bearing face and a thread that runs the full length up to that face. The recorded item on this page is carbon steel with a blue-white zinc finish and a combination recess — a Phillips cross with a straight slot across the head — quoted from M1 to M14 with Number 818.
Pan head. A low dome, with a height of just under half its diameter and a flat bearing face. It spreads the clamp load on a thin panel and leaves a smooth profile that does not catch on the next component.
Full thread. The coarse self-tapping thread runs all the way to the bearing face. On a single-thickness joint or a through-bolted assembly that gives grip along the whole engagement, which is the opposite of a half-thread screw.
Combination recess. A Phillips cross with a slot cut across the full head diameter. Either bit drives the screw, which is useful on assemblies that are serviced with whatever tool is at hand.
Gimlet point. Sharp, tapered and on centre, so the screw starts its own hole in timber, board or plastic. It has no cutting flute and no drill point; those suit different materials.
Together these decide the joint: the full thread grips through the thickness, the pan head draws it up, the combination recess takes either bit, and the gimlet point starts the hole. That is why a tapping screw pan head of this type is specified by thread length, point, head and drive together.
The body of a tapping screw pan head of this type is carbon steel wire, with the grade and heat number kept with the batch record. The property class is fixed on the drawing, because it sets the driving torque the head can take while the coarse thread is cutting.
The pan head is formed in the heading die with a small fillet into the shank. The fillet carries the drive torque into the body, and on a full-thread screw the first thread sits directly under it, so the transition is where the load is highest.
The thread is rolled full length to the bearing face. Rolling keeps the grain continuous and gives a smooth flank, and it produces the coarse form that grips in timber and board without a tapped hole.
The combination recess is formed in the same heading stroke and the slot cut across the full diameter afterwards. Both features are checked with their own tools, because the Pozi-style cross engages the bit differently from the slot.
The blue-white zinc is applied after forming and before packing. It is thin, so the thread keeps its form and the point keeps its taper, and the recess keeps the depth the bit needs.
Tapping screws of this type are quoted from M1 to M14; the recorded configuration covers that range in carbon steel with a blue-white zinc finish, a full thread and a pan head. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission.
| Item | How it is defined | What we control |
|---|---|---|
| Head diameter and height | The pan head that bears on the panel | Checked on the projector on the first article |
| Thread length | Full length up to the bearing face | Checked on the first article |
| Thread pitch | The grip in the material | Gauged per batch |
| Point form | Gimlet, on centre | Checked on the first article |
| Length | Under the head to the point | Measured on the shop plate |
| Coating | Blue-white zinc film | Checked on the sample |
Each size is quoted against the material it enters. The thread pitch, the thickness of the timber or board and the head diameter are reviewed together, because a coarse thread that is right for softwood splits a harder board and a head that is right for a thin panel crushes a soft one.
On a tapping screw pan head, length is measured from under the head to the point. On a full-thread screw the thread length equals the length, which is the difference between this part and a half-thread screw of the same size.
On a tapping screw pan head the full thread is the defining feature. Every turn of the thread grips, so the screw holds along its whole engaged length — which is what you want in a single layer, a through-fixed board or a joint where the screw does not pass through a clearance layer.
| Thread form | Where the grip is | Best for | What to watch |
|---|---|---|---|
| Full thread | Along the whole length | Single layer, through-fix, thin assemblies | The thread also grips any upper layer it passes through |
| Half thread, long shank | Only at the tip | Two-layer joints pulled together | Thread start must match where the layers meet |
| Machine thread | Tapped hole or nut | Serviced joints and repeated assembly | Needs a tapped hole, not an own-thread |
The combination recess is the second practical feature. On a screw that is driven once into timber or board, the risk is a stripped head rather than a stripped thread; having both a cross and a slot means the fitter can switch tools rather than force the driver.
The gimlet point and the full thread work together. The point starts the hole and the first thread bites immediately, so the screw does not need a pilot in soft material. In hard board or near an edge, a pilot hole is still used — the point is not a substitute for the material’s own limits.
Blue-white zinc keeps the part bright and protects the steel indoors. On a self-tapping screw the finish is judged at the point and the thread crests, because those are the surfaces that scrape as the screw enters.
This tapping screw pan head is supplied blue-white zinc plated. The zinc is sacrificial and the clear passivation keeps the appearance bright; because it is a thin deposit, the coarse thread keeps its cutting form and the point keeps its taper.
| Finish | How it protects | Effect on thread and point | Typical use |
|---|---|---|---|
| Blue-white zinc | Sacrificial zinc, clear passivation | Thin; thread and point as formed | Indoor timber, board and panel work |
| Yellow zinc | Sacrificial zinc, yellow passivation | Thin; gauged after | Indoor parts where a warmer tone is accepted |
| Dacromet | Zinc-aluminium flake layer, cured | Thin film; point re-checked | Outdoor assemblies |
| Zinc nickel | Alloy layer, higher corrosion resistance | Thicker; thread re-checked | Wet industrial service |
| Stainless (equivalent part) | Alloy provides protection | No coating | Wash-down and coastal work |
Salt-spray exposure is agreed per project and written on the drawing. On a self-tapping screw the coating has to survive abrasion as well as corrosion, because the point and the thread crests scrape the material on the way in.
Packing protects the points and the heads of a tapping screw pan head. The parts are bagged in counted quantities, labelled with the batch, the material heat and the drive type, and packed so the points cannot knock against each other.
Three joints where a full thread and a dual drive are the right combination:
| Where it sits | The screw passes through a single board or a batten and grips along its whole length, with the pan head bearing on the face. |
| When it goes wrong | A screw that grips only at the tip holds less in a thin section, and a point that wanders misplaces the fixing. |
| Why it happens | The material is timber or composite, the joint is made once, and the head is left visible or plugged. |
| What we control | Thread and point checked, and the first article driven into a sample of the same board. |
| Where it sits | The screw fixes a panel to a light frame where the thread engages through the panel and the head spreads the load. |
| When it goes wrong | A coarse thread in thin sheet strips out, and a head that is too small pulls through. |
| Why it happens | The sheet is thin, the frame is soft, and the joint is inspected. |
| What we control | Thread pitch and head diameter matched to the gauge on the drawing. |
| Where it sits | The screw holds a bracket, a hinge or a connector where the thread runs full length into the board. |
| When it goes wrong | A head that splits the board ruins the component, and a stripped recess stops the assembly on the line. |
| Why it happens | The boards are pre-drilled, the screws are driven at speed, and the joint is made once. |
| What we control | Recess checked with both tools, and the thread matched to the board. |
Four reasons that matter on a full-thread self-tapping screw, each tied to what the drawing has to prove:
|
Thread, material and head reviewed together
The thread pitch, the material the screw enters and the head diameter are reviewed before tooling, so a screw that would split the board or strip the sheet is raised first. Basis: Thread, material and head reviewed before tooling. |
Head, recess and thread in one route
The pan head, the combination recess and the full thread come off one route, with the slot cut across the finished head. Basis: One route from wire to finished screw. |
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Both drives and the point checked
The recess is checked with a cross bit and a flat blade, and the point and thread on the first article. Basis: First article checked with both tools. |
First article to repeat production
Everything that decides the batch – drawing revision, wire heat, die set, thread roll – is fixed at the first article and reused for repeats. Basis: First article signed off before the batch is released. |
Shi Shi Tong forms these tapping screw pan heads on a single-die header that upsets the pan head and the recess in one stroke, cuts the slot across the head, then rolls the coarse thread full length and forms the gimlet point. The parts are cleaned and blue-white zinc plated. The first part of every run is measured on the head and the point, driven with both tools and gauged on the thread before the batch continues.
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Between runs the die insert is changed to the drawing head and the rolls to the pitch; the first part goes to the projector and to the gauges. The slot is cut into the finished head, so the slot depth is checked on the same first part as the head, because the two features share the same material.
What decides whether a tapping screw pan head passes is the head diameter and height, the recess in both configurations, the thread form and pitch, the point and the coating. The inspection agreement covers those, and the criteria come from the drawing.
Head and recess on the projector |
Thread gauged per batch |
Hardness testing against the property class |
Salt-spray testing of the plated part |
Each batch is recorded against the drawing revision: head, slot and point from the first article, the thread gauged per batch, and the plating batch carried on the label. If either drive or the point check fails, the parts back to the last good setting are held and re-checked.
Where the drawing asks for a third-party report, it is ordered alongside the batch and filed with the inspection record under one batch number.
Every shipment of tapping screw pan heads is traceable to the wire it was made from. The grade, heat number and property class are recorded on the material certificate supplied with the parts, and the inspection records follow the criteria agreed on the drawing.
ISO 9001:2015 |
RoHS test report |
Registered trademark |
Patent: security screw and driver |
With each batch we supply the material certificate, the inspection record for the criteria on the drawing and, where it is listed, the third-party report for the material or the finish. The documents carry the drawing revision and the batch number, so the paperwork can be matched to the parts.
More than 8,678 customers in 89 countries and regions have ordered from Shi Shi Tong; 87% of orders come from repeat customers and 56% through referrals. Most projects follow the same route: drawing review, first-article approval, then batches checked against that sample. On a self-tapping screw the first article is driven into a sample of the customer’s material, so the point and thread are signed off in the work they hold. Buyers visit during the process to review samples and to see how the points are formed.
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8,678+
customers served
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87%
of orders from repeat customers
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56%
of orders through referrals
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89
countries and regions shipped to
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Buyers and quality engineers visit for sample review, process discussion and supplier audits; the visit is arranged around production so the header and the plating line can be seen on the day the parts run.
Customer group visit – sample review |
Customer group visit – process discussion |
Customer group visit – factory tour |
Customer visit – project kick-off |
Danish customer – drawing review |
Industry exhibition – meeting customers |
It is a self-tapping screw with a low domed head. This one has a full-length coarse thread, a combination recess with a cross and a slot, and a gimlet point, in carbon steel with a blue-white zinc finish.
A full thread grips along the whole engaged length, which suits a single layer or a through-fix. A half thread leaves a plain shank that clears the top layer so the joint can be pulled together.
Timber, board and moulded plastic. In sheet metal a drill point is used, which is a different part with a different tip.
Yes. The combination recess takes a Phillips cross bit or a plain flat blade, and both are checked on the first article.
Blue-white zinc, the standard indoor protection for steel tapping screws. For outdoor joints a Dacromet or stainless version is the better choice.
Thread size and pitch, thread length, point form, head diameter and height, drive type, length and datum, material and property class, finish, and the material the screw enters.
How a tapping screw pan head project runs from drawing to repeat delivery:
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1
Send the drawing or sample
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2
Thread, head and material review
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→ |
3
First article in the material
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→ |
4
Batch production and repeat orders
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Each step is confirmed with you before the next one starts; the drawing revision from the first article is what repeat orders are checked against.
For a quotation, send the drawing with the thread size and pitch, thread length, point form, head diameter and height, drive type, length and its datum, material and property class, finish, and the material the screw enters.
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Thread and pitch
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Thread length
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Point form
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Head and drive
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Length and datum
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Material and finish
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Sending a drawing? The form below does not take attachments. Email the PDF, DXF or STEP file to sst@szsst88.com with the part name and quantity in the subject line – the drawing is reviewed and a quotation follows.
+86 13143444311
sst@szsst88.com
