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+86 13143444311
Email：sst@szsst88.com
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Address：Building 9, First Industrial Zone, Tantou Industrial City, Songgang Street, Baoan District, Shenzhen 518105, Guangdong, China
Type:Self tapping screw with an integral pan washer head, Phillips drive, coarse full thread and sharp point (Non-Standard)
Materials:Carbon Steel
Surface treatment:White zinc plated, bright electroplated finish
Head Type:Pan washer head: low pan dome with a wide thin integral flange formed from the same wire; the flat underside of the flange is the bearing face; no separate washer
Drive:Phillips cross recess, four tapered wings with a pointed centre; no slot
Thread:Coarse single lead self tapping thread, full length from the flange underside to the point; no plain shank
Point:Sharp tapered gimlet point; no drill point, no cutting slot
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Forming:Single-die cold heading, pointing, thread rolling, white zinc electroplating, gauging and sorting
Number:773
We manufacture self tapping screws with washer: a pan washer head with a wide thin integral flange, a Phillips recess, a coarse self-tapping thread and a sharp gimlet point, in carbon steel with bright white zinc. Flange diameter and thickness, point, thread and length 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.
Self tapping screws with washer are screws whose head carries an integral washer flange, so the bearing area of a washer arrives with the fixing instead of as a separate part. The recorded item on this page has a pan washer head with a wide thin flange, a Phillips recess, a coarse thread over the full length and a sharp gimlet point, in carbon steel with a bright white zinc finish, quoted from M1 to M14 with Number 773.
Washer formed into the head. The flange is the same wire as the head, formed in the heading stroke, and its flat underside is the bearing face. Nothing has to be picked up, placed or counted, and nothing can be left out on the line.
Self tapping. The coarse thread rolls its own path in a prepared hole, so the screw holds in sheet, board and plastics without a nut. It is not a machine screw: there is no tapped hole waiting and no plain shank to guide it.
Sharp gimlet point. The point starts in the hole and leads the thread in. In timber and board it makes its own start; in sheet metal it needs a drilled or punched hole to enter.
White zinc. A bright electroplated zinc with a blue-white passivation. It is the standard indoor finish for steel self-tapping screws: thin, bright, sacrificial, and it does not fill the recess.
Together these decide the joint: the flange spreads the load, the thread holds in the material, the finish keeps the part bright, and the point starts where the hole has been prepared.
The pan dome and the integral flange are upset in one heading stroke. Forming them together is what makes the flange flat and continuous: a flange that was pressed on afterwards would be a separate ring that could move, and a flange that was cut would leave burrs under the bearing face.
The flange is thin and wide. Thin lets it follow the panel and spread the load; wide puts the bearing area where the material needs it. The trade is stiffness — a thin flange can dish under heavy torque — so self tapping screws with washer of this type are driven to a stated torque and the flange is checked after driving.
The thread is rolled from the flange underside to the point, with no plain shank, so the whole length below the head is engagement. It is a coarse single-lead thread, which is what gives grip in the materials these screws are specified for.
The gimlet point is formed after rolling. That order matters: forming the point afterwards gives it a clean taper and a lead-in, while forming it before rolling would let the roll blunt the tip.
White zinc is applied last, over the flange, the recess and the point. It adds a few microns, so the thread is gauged after plating and the recess is driven with the production bit in the plated condition.
The family is quoted from M1 to M14, with M1, M2, M3, M4, M5, M6, M7, M8, M9, M10 and M14 in the recorded range. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission; self tapping screws with washer are normally short, because the thread holds through a panel rather than clamping a stack.
| Item | How it is defined | What we control |
|---|---|---|
| Thread | Coarse single-lead self-tapping, full length | Gauged per batch after plating |
| Head dome | Low pan dome, set by the DIN form recorded | Checked on the projector |
| Flange diameter | Wide and thin, integral with the head | Measured on the first article |
| Flange thickness | Thin enough to follow the panel | Checked on the section |
| Recess | Phillips cross | Driven with the production bit |
| Point | Sharp gimlet | Checked on the first article |
| Length | From under the flange to the point | Measured on the shop plate |
Length is measured from under the flange, because that is the face that bears. It is not the same as measuring from the dome: the flange thickness is the difference, and on a shallow counterbore that difference decides whether the screw bottoms before the flange seats.
The flange diameter is the number that decides both the bearing area and the clearance. A wider flange covers an oversized hole and spreads load further, but it also needs room around the head and leaves a wider footprint if the finish is disturbed. It is quoted with the head diameter rather than left to the standard.
The point of this part is the washer, and it is worth being clear about when an integral flange beats a separate washer and when it does not.
| Feature | What it gives | What it costs |
|---|---|---|
| Integral flange | No separate part to fit or lose | Cannot be swapped for a different washer |
| Thin flange | Follows the panel and spreads load | Can dish under heavy torque |
| Self-tapping thread | Holds without a nut | Needs the right pilot hole |
| Gimlet point | Clean start in wood, board and plastics | Not for sheet metal without a drilled hole |
| White zinc | Bright sacrificial finish | Thin; not for outdoor or coastal work |
An integral flange wins on the line. A loose washer is a second part to stock, pick and place, and the failure mode is silent: the screw goes in without its washer and nobody notices until the paint cracks around the head. A formed flange cannot be left off, and it cannot be double-fed either.
A separate washer still wins in two cases. Where the joint needs a hardened washer under a high preload, the formed flange is too thin and too soft. Where the surface must not be marked at all, a nylon or fibre washer does something the steel flange cannot.
The flange is not there to make the screw stronger; it is there to spread load and to protect the face. Its diameter is chosen for the panel, not for the thread, which is why the drawing should quote it separately.
The recorded finish is bright white zinc with a blue-white passivation. It is thin, bright and sacrificial, and on a washer head the flange edge is the place where that difference shows.
| Finish | How it protects | Effect on flange and thread | Typical use |
|---|---|---|---|
| White zinc | Sacrificial zinc, blue-white passivation | A few microns; gauged after | General indoor assembly |
| Yellow zinc | Sacrificial zinc, yellow passivation | A few microns; gauged after | Warm-tone indoor hardware |
| Black zinc | Zinc with black passivation | A few microns; recess re-checked | Dark panels |
| Dacromet | Zinc-aluminium flake layer, cured | Thin film; flange and thread re-checked | Outdoor and wet assemblies |
| Stainless (equivalent part) | Alloy provides protection | No coating | Wash-down and coastal work |
The flange edge is a cut edge and it takes the deposit differently from the flat face, so on a bright zinc part the rim can look slightly different in tone. That is normal for an electroplated flange and it is not a defect, but it is worth saying so before a customer sees a batch and wonders why the edges differ.
Zinc is sacrificial, so a scratch on the flange is protected by the zinc around it — that is the practical reason these screws are specified in white zinc rather than black oxide. On a joint that is indoors and handled, it is enough. On a joint that is washed or outdoors, it is not, and a Dacromet or stainless version of the same head is the honest specification.
Three assemblies where a flange that cannot be lost or left out is the point:
| Where it sits | The screw fixes a panel, a back plate or a bracket to a frame where hundreds of fixings are placed per shift and the flange protects a painted or coated face. |
| When it goes wrong | A loose washer is dropped, double-fed or forgotten, and a missing washer leaves the head bearing on the coating it damages. |
| Why it happens | The volume is high, the parts are picked by hand or fed automatically, and a missing washer stops the line. |
| What we control | Flange diameter and flatness checked, thread gauged after plating, first article driven in a coated sample. |
| Where it sits | The screw joins board or a composite panel where the flange spreads the load on a soft face and the head does not pull in. |
| When it goes wrong | A plain head sinks into the board, and a separate washer that is forgotten lets it happen. |
| Why it happens | The material is soft, the fixing is visible, and the assembly is made on a bench or a line. |
| What we control | Point form checked against the board sample, flange diameter against the face. |
| Where it sits | The screw closes a cover or fixes a guard on a coated steel skin, where the flange both spread the load and protected the finish. |
| When it goes wrong | A narrow head concentrates load and cracks the coating around the hole, and a bright bare head reads as a repair on a coloured panel. |
| Why it happens | The panel is coated and thin, the fixing is seen, and the joint is serviced. |
| What we control | Flange checked for burr and flatness, and the coating around a sample hole inspected after driving. |
Four reasons that matter on a thin-flange screw, each tied to what the drawing has to prove:
|
Flange and torque reviewed together
The flange diameter and thickness, the point form and the joint torque are reviewed as one set, so a flange that would dish under the production torque is raised first. Basis: Flange and torque reviewed as one set. |
Head and flange in one stroke
The pan dome and the integral flange are upset in one heading stroke, so the flange is formed from the same wire and cannot shift. Basis: Flange formed with the head. |
|
Flange and recess checked on the part
The flange is checked for flatness and burr, and the recess is driven with the production bit after plating. Basis: First article driven with the production bit. |
First article to repeat production
The first article fixes the drawing revision, wire heat, die set, thread roll and plating, and repeat orders are compared with that record. Basis: First article signed off before the batch is released. |
Shi Shi Tong forms these self tapping screws with washer on a single-die header that upsets the pan dome and the wide thin flange in one stroke, points the blank, rolls the coarse thread from the flange underside and finishes the parts in bright white zinc. The first part of every run is measured on the flange, gauged after plating and driven into a sample of the customer’s material, before the batch continues.
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The flange is where the die shows its age. A worn die leaves a flange that is slightly thicker at one side, and a flange that is not uniform will dish unevenly when driven — the head then leans and the joint reads as loose without any visible cause. The flange is checked on the section of the first article and sampled through the run.
What decides whether self tapping screws with washer pass is the flange, the head, the recess, the thread, the point and the plating. The inspection agreement covers those, and the criteria come from the drawing.
Head and flange on the projector |
Thread gauged after plating |
Hardness testing against the property class |
Salt-spray testing of the white zinc plate |
The flange is checked by driving the first article into a sample panel and looking at the contact ring and the flatness afterwards. A flange that is flat on the bench and dished after driving has told you the joint torque is above what that flange thickness will take.
The recess is checked after plating with the production bit, because the zinc narrows the cross by a few microns and on the small sizes that is enough to make the bit tight. The point is checked in the same sample: a gimlet that is blunt will skate on thin sheet and mark the panel.
Every shipment of self tapping screws with washer is traceable to the wire it was made from and to the plating batch. The grade and heat number are recorded on the material certificate supplied with the parts, the plating thickness is recorded per batch, 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 plating. 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 washer head the first article is driven into a sample of the customer’s material, because the flange and the point only prove themselves against the panel they meet. Buyers visit during the process to review samples and to see how the heads 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
|
89
countries and regions shipped to
|
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 |
A screw whose head carries a flange formed from the same wire, so the bearing area of a washer arrives with the fixing and there is no separate part to fit or lose.
For spreading load, yes. For high preload on a hard surface, a separate hardened washer is still better, because the flange is thin and made of the same steel as the screw.
It can, under torque above what that thickness will take. The joint torque is set from the first article, and the flange is checked for flatness after driving.
A sharp gimlet point for timber, board and plastics. In sheet metal the hole is drilled or punched first; the point enters it, it does not make it.
Bright white zinc, which is the standard indoor finish: thin, bright and sacrificial. For outdoor joints a Dacromet or stainless version is the right choice.
Thread size and pitch, head and flange diameter, flange thickness, recess size, point form, length and datum, plating and the panel material.
How a self tapping screw with washer project runs from drawing to repeat delivery:
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1
Send the drawing and a material sample
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→ |
2
Flange and point review
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→ |
3
First article driven in the sample
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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, head and flange diameter, flange thickness, recess size, point form, length and datum, plating and the material being joined.
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Thread and pitch
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Head and flange
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Flange thickness
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Point form
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Length and datum
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Material and plating
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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
