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+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:Truss Head Machine Screw Cross Recessed
Materials:Carbon Steel
Surface treatment:Nickel Plated
Head Type:Truss Head
Drive:Phillips (cross)
Thread:Machine thread, half thread
Point:Blunt
Forming:Single Die Heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Number:707
We make truss head machine screws in nickel plated carbon steel, with a wide low head, a Phillips recess and a half thread, quoting them from M1 to M14. Head diameter and height, rim form, recess and thread length come from your drawing, and the first article is fitted on your panel.
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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.
These truss head machine screws have a wide, low head on a short cylindrical bearing face, a Phillips recess and a half thread, in nickel plated carbon steel, quoted from M1 to M14 with Number 707. The head is the reason the part exists: it spreads the clamp further than any other common head of the same thread.
Truss head. A broad, low head with a thin edge, made to spread load on thin or soft material without a washer.
Phillips recess. A cross cut into the head and driven with a PH bit.
Half thread. The plain shank runs through the joint and the thread engages only at the far end.
Nickel plating. A bright barrier deposit over carbon steel, for visible indoor work.
Truss head machine screws are chosen where a thin panel or a soft face has to be clamped without a washer and without dishing: covers, coated plates and cabinet panels, where the head is seen and its area matters more than its height.
A truss head is defined by its ratio: wide relative to its height, with a rim that curves down to a flat bearing face. On a truss head machine screw that shape is the whole specification — the bearing area, not the thread, is what decides whether a thin panel survives being clamped.
The thin rim is the cost. Because the head has little height, it flexes if the surface beneath it is not flat; on a rough casting the rim bends and the area that was supposed to spread the load is lost, while the head still looks seated. A truss head needs a flat seat as much as a wide one.
The half thread belongs to the joint. The plain shank passes the front parts so they are not threaded, and the thread engages at the far end; on a screw whose head spreads load over a thin panel, that division keeps the panel from being cut into a nut.
Nickel is the finish that suits the head. A barrier deposit holds a bright, even colour across a wide flat surface, and on a part that is visible for its area rather than its height, that evenness is what the eye reads.
The recess is the torque limit. A truss head of this diameter has room for a cross, but the head is thin at the rim, so the screw is tightened to what the head will take rather than to what the thread could carry — and on a thin panel that is the right limit anyway.
The recorded range is M1 to M14, with lengths made to the drawing. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission. For truss head machine screws the quotation carries head diameter and height, rim form, recess depth, thread length and finish.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Truss, wide and low | Head diameter, height and rim form |
| Recess | Phillips cross | Recess size and depth |
| Shank | Plain section through the joint | Diameter and length |
| Thread | Half thread | Thread length, pitch and gauging |
| Material | Carbon steel | Grade and heat number on the certificate |
| Finish | Nickel plated | Thickness and colour |
| Seat | Surface under the head | Flatness needed for the rim |
Head diameter is the functional number. It is quoted against the panel it bears on, because the point of the head is the area; a truss head one size down no longer spreads the load the drawing intended.
Rim condition matters as much as diameter. A truss head has a thin edge, and a burr or a rolled edge on it will mark the panel it is supposed to protect.
Three features define the part: the wide head, the thin rim and the half thread. The first spreads the load, the second is the limit on how flat the seat has to be, and the third keeps the front of the joint unthreaded.
| Feature | What it gives | What it costs |
|---|---|---|
| Wide head | Largest spread of the common heads | Needs clearance around the hole |
| Thin rim | Low profile on a wide head | Flexes on an uneven seat |
| Half thread | Front part stays unthreaded | Both lengths must be specified |
| Phillips recess | Common bit, fast drive | Shallow in a thin head |
| Nickel plating | Bright barrier finish | A scratch becomes a rust point |
The spreading is the reason for the head. On a panel that has no room for a washer, or where a washer would be lost in service, a truss head is a permanent washer formed on the screw.
The thinness is the reason the drive is modest. A shallow cross cams out easily, so the torque has to be set to the recess and the bit has to fit.
The recorded finish is nickel plating over carbon steel. It is a barrier deposit: bright, hard and even, which is exactly what a wide flat face wants. The trade is that a scratch is a rust point, because there is no surrounding coating to protect the damage.
| Option | How it protects | Effect on head and thread | Typical use |
|---|---|---|---|
| Nickel plated | Barrier deposit, bright | Thin build; recess re-checked | Visible indoor assemblies |
| Zinc plated | Sacrificial zinc | Thin build; recess re-checked | General indoor work |
| Black oxide | Conversion film, oiled | No measurable build | Internal mechanisms |
| Black zinc plated | Sacrificial zinc, dark | Thin build; wear visible | Dark housings |
| Stainless alternative | Passive film, no build | Head and thread as made | Wet and food service |
Where the panel is coated and the head is wide, the finish on the rim is what matters: a rough deposit there marks the panel at the very edge the head was meant to protect.
Where the joint is wet, stainless is the specification and the rim is the reason: a thin plated rim loses its coating first, and the rust then shows across the widest part of the head.
Three assemblies where truss head machine screws are the fixing:
| Where it sits | The screw holds a cover where there is no room for a washer and a narrower head would dish the panel. |
| When it goes wrong | The panel dimples anyway, because the head is bearing on a rough or uneven face. |
| Why it happens | The panel is thin, the head is wide, and the seat is not machined. |
| What we control | Head diameter and rim checked; first article fitted on the panel. |
| Where it sits | The screw fixes a plate where the head bears on a painted or laminated surface and must not cut a ring. |
| When it goes wrong | The head marks the coating, and the mark is wider than the head because the rim flexes. |
| Why it happens | The surface is coated, the head is wide, and appearance matters. |
| What we control | Rim and coating checked; first article fitted on the finished face. |
| Where it sits | The screw joins a panel at a shallow seat where the head has to spread the clamp without a washer. |
| When it goes wrong | A narrow head cuts into the board, and the fixing pulls through. |
| Why it happens | The board is soft, the head is visible, and the joint is light. |
| What we control | Head diameter and thread checked; first article driven into a sample. |
Four reasons that matter on a wide thin head, each tied to what the drawing has to prove:
|
Head diameter and rim agreed
Head diameter, head height and rim form are agreed together, because on truss head machine screws the area is the function and the rim is what protects it. Basis: Head diameter and rim agreed. |
Formed, recessed, plated in one route
The wide head and the cross recess are formed in one stroke, the half thread rolled and the parts nickel plated within one route. Basis: One route from wire to plated screw. |
|
Rim checked for burr
The rim is checked for burr and edge condition under magnification, because a thin rim is what marks the panel it protects. Basis: Rim checked for burr. |
First article on the panel
The first article is fitted on the customer panel, because how the head spreads is a property of the pair. Basis: First article fitted on the panel. |
Shi Shi Tong forms these screws on single-die headers that upset the wide head and cut the Phillips recess, then rolls the half thread and nickel plates the parts. The first part of every run is measured on head diameter, head height, rim form, recess depth and thread before the batch continues.
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Forming a thin, wide rim is the hardest part of a truss head. The metal has to be pushed outward to the diameter without tearing at the edge, and the rim that results is a fraction of a millimetre thick; a punch that is slightly worn leaves a rim that is thick on one side and thin on the other, and the head flexes unevenly.
What decides whether truss head machine screws pass is the head diameter and height, the rim, the recess and the thread. The inspection agreement covers those, and the criteria come from the drawing.
Head and rim on the projector |
Thread gauged per batch |
Hardness checked on the wire |
Coating proved by salt spray |
The head is measured for diameter and height, the rim for thickness and for burr, and the recess for size and depth. The thread is gauged after plating, and the coating is checked for colour across the face.
The first article is seated on the customer panel and checked for whether the rim sits flat. A truss head that is slightly domed at the rim will mark a soft panel even when the head measures correctly.
Every shipment of truss head machine screws 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, 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 coating. The documents carry the drawing revision and the batch number, so a repeat order keeps the same head diameter and rim.
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 truss head machine screws the first article is fitted on the customer panel, because the spread of the head is the function. Buyers visit during the process to review samples.
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8,678+
customers served
|
87%
of orders from repeat customers
|
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 headers 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 |
The truss head is wider and lower, so it spreads the same clamp over more area; on a thin or soft panel that is what stops the hole dishing.
Only if the seat is uneven or the rim has a burr. The rim is checked, and the first article is fitted on the panel.
No. A thin head has a shallow recess, so the torque is set to the recess rather than to the thread.
The plain shank passes the front part and the thread engages at the far end, so the panel is not threaded into a nut.
It adds a thin layer; on nickel the colour is checked across the face, and the recess after plating.
Head diameter and height, rim form, recess size and depth, thread length, the grade and the finish.
How a truss head machine screw project runs from drawing to repeat delivery:
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1
Send the drawing and the panel it bears on
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→ |
2
Head diameter, rim and thread agreed
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→ |
3
First article fitted on your panel
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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 head diameter and height, rim form, recess size and depth, thread length, the grade and the finish.
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Head diameter
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Head height
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Rim form
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Recess depth
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Thread length
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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
