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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:MDF Screws
Materials:Stainless Steel
Surface treatment:Plain
Head Type:Countersunk flat head
Drive:Phillips cross recess
Thread:Machine thread with nylon patch
Point:Plain, chamfered
Forming:Cone formed; thread cut; patch applied
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10
We make MDF screws in stainless steel with a countersunk head, a Phillips recess and a nylon patch on the thread, quoted from M1 upward to the drawing. The cone angle is matched to your countersink and the patch is kept clear of the head, so the first article sits flush in your board.
Watch the factory video·Email sst@szsst88.com
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.
MDF screws are small screws used to fix hardware into medium-density fibreboard and similar engineered panels, usually with a countersunk head that sits flush with the surface. The part recorded here is stainless steel left plain, small stainless screws with a Phillips recess and a thread-locking patch, quoted from M1 upward.
Countersunk head. A cone-shaped head that sits inside a matching countersink so the surface stays flat.
Phillips recess. A cross recess sized to the small head, driven with a standard bit.
Thread-locking patch. A pre-applied nylon patch on the thread that resists loosening in a joint that is opened and closed.
They are used in furniture, cabinet and panel assemblies, where the fixing has to disappear into the board and stay tight as the assembly flexes. The head form is what makes them specific to board work: a flush cone, sized to the countersink the board is machined with, rather than a head that stands above the surface.
A countersunk screw does not bear on a flat face; it bears on a cone. The head is a truncated cone that sits in a matching countersink, and the joint looks right only when the two cones agree in angle and depth. That is a different requirement from any other head form, and on MDF screws it is the requirement that decides most of the design.
The angle is the first part. A countersink cut at a different included angle from the head will contact on a line rather than on a face: the head rocks in the seat, the surface shows a ring where the cone met the board, and the screw is not actually supported. Ninety degrees is the usual pair, and it has to be stated as a pair rather than assumed on one side only.
The material is the second. MDF and similar boards are soft and friable: the countersink is not machined metal but compressed fibre, and it yields under the head. Over-drive the screw and the cone crushes, so the head sinks below the surface; under-drive it and the head stands proud. On wood and board the flush finish therefore depends on the driver stopping at the right force, which is why these small screws are normally run down to a clutch setting rather than by feel.
The patch on the thread interacts with all of this. A nylon patch is applied to the thread to stop the screw backing out of a joint that is opened and closed; but if the patch runs up to the head, it becomes a spacer between the cone and the countersink. The head then sits a few hundredths high, the fibre never sees the full contact, and the flush finish is lost. On the MDF screws in the photo the patch is on the thread and nowhere else, and that boundary is a drawing dimension.
The last constraint is thickness. A countersink removes material from the board at exactly the place where the screw is also entering it, so a thin panel can be weakened or pierced by the cone. The screw size, the countersink depth and the panel thickness have to be chosen together, and on a 12 mm board a large countersunk screw leaves very little material under the cone.
The part is quoted to the drawing with the head, the thread and the panel stated separately. Custom lengths up to 2,000 mm, subject to DFM review after drawing submission. The quotation for MDF screws carries the head diameter and angle, the thread size and pitch, the length under the head, the patch position and the panel thickness.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Countersunk cone | Diameter, angle and cone finish |
| Recess | Phillips | Depth and width |
| Thread | Machine or coarse | Size, pitch and length |
| Patch | Nylon on the thread | Position and length, off the cone |
| Panel | MDF or similar | Thickness and countersink depth |
| Pilot | In the panel | Agreed size and depth |
On MDF screws the head diameter and angle are one dimension pair. A head that is the right diameter but a different angle will not seat in the customer’s countersink, and one that is the right angle but too small will pull through the cone on a soft board.
On MDF screws the patch position is stated from the underside of the head, so there is a measurable gap between the cone and the first turn of nylon. That gap is what keeps the head flush.
For MDF screws the thread itself depends on what it goes into. Into a threaded insert or a nut it is a machine thread; into the board directly it has to be coarser and usually needs a pilot hole, because a fine thread in MDF will strip the fibre rather than cut it.
Four properties decide MDF screws of this kind, and each one carries a cost:
| Property | What it gives | What it costs |
|---|---|---|
| Countersunk head | Flush surface | Cone angle must match the board |
| Nylon patch | Holds under vibration and re-opening | Raises the driving torque |
| Stainless body | No rust marks on light board or fabric | Softer than steel in soft fibre |
| Small size | Disappears into thin panels | Little margin in the countersink |
The value is a fixing that is invisible from the surface and stays tight. On furniture and cabinet work both matter: a proud head shows through a finish, and a screw that backs out of a fibre board leaves a hole that cannot be repaired without moving it.
The cost is that the joint is soft on one side. The screw is stronger than the material it sits in, so every torque decision is really a decision about the board, and the countersink is the feature that carries it.
The recorded finish is plain stainless steel. On a fixing that goes into a light board, stainless leaves no rust mark if moisture reaches the joint, and the patch needs a clean, film-free thread to key to; a plate under the patch is another layer that can shear away.
| Option | How it protects | Effect on cone and thread | Typical use |
|---|---|---|---|
| Plain, passivated | Passive film, no coating | Cone and thread as formed | Board and furniture work |
| Passivated 304/316 | Cleaner passive layer | No build; free-machining option | Damp and food areas |
| Nickel plated | Hard bright barrier | Thin build; cone re-checked | Visible decorative fixings |
| Zinc plated | Sacrificial zinc | Build on cone; patch key affected | Cost-driven dry joints |
| Black oxide | Conversion film, oiled | No measurable build | Dark furniture hardware |
Where an MDF screw head is visible until it is covered by a finish, the cone is the surface that matters: a plate on the cone changes the seating depth, and on a flush fixing a few hundredths is visible.
On MDF screws with a patch, a coating between the thread and the nylon reduces how well the patch keys. Plain stainless keeps that interface as bare metal, which is why it is the usual choice for patched small screws.
Three assemblies where a flush head in a soft panel is the requirement, and where MDF screws are the usual answer:
| Where it sits | The screw fixes a hinge plate, a runner or a bracket into a board where the surface will be seen and finished. |
| When it goes wrong | The head stands proud, or the countersink crushes and the head sinks. |
| Why it happens | The cone angle differs from the countersink, or the screw is driven without a clutch. |
| What we control | Cone angle and depth agreed; first article driven into the board and measured flush. |
| Where it sits | The screw joins panels that are assembled and taken apart again during installation. |
| When it goes wrong | The joint loosens, and the fitting shifts after the second assembly. |
| Why it happens | There is no locking feature, and the fibre does not hold the thread. |
| What we control | Patch position and torque checked; first article assembled and re-opened. |
| Where it sits | The screw holds a panel or a trim where the surface has to stay flat for a graphic or a finish. |
| When it goes wrong | The head telegraphs through the finish, or the panel cracks at the countersink. |
| Why it happens | The board is thin, and the countersink is too deep. |
| What we control | Panel thickness and countersink depth checked on the first article. |
Four reasons that matter on MDF screws whose job is to disappear, each tied to something the drawing or the first article proves. All four show in the sample.
|
Cone angle and patch position agreed
The head angle and the distance from the cone to the patch are both stated, because either one can hold the head off the surface. Basis: Cone and patch dimensioned. |
Cone formed, thread cut, patch applied
The cone is formed with the head, the thread cut, and the patch applied afterwards on the thread only. Basis: Patch off the cone. |
|
Seated flush in the board
The first article is driven into the customer board at the intended torque and measured for flushness, not just for size. Basis: Flushness proved in board. |
Same seat on repeat runs
Cone angle, patch position and torque are recorded with the drawing revision, so a repeat batch sits the same way. Basis: Same seat across orders. |
These screws are turned and threaded from stainless wire and bar, with the countersunk head formed, the cone ground or turned to its angle, the cross recess cut, the thread formed, and the nylon patch applied to the thread; the parts are passivated and inspected. The first piece of every run is measured on head diameter and cone angle, recess depth, thread, and patch position.
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On MDF screws the cone is the feature that decides whether the part sits flush. It is cut to its included angle on the same axis as the thread, and the junction between the cone and the shank is kept sharp; a radius left there lifts the head by the size of the radius, and on a flush fixing that is visible across a whole panel.
Applying the patch is where the boundary matters. The nylon is fused onto a defined span of thread, and the spacing from the underside of the head is set so the cone never sees nylon. A patch that creeps up to the head becomes a spacer, and the screw sits proud no matter how carefully it is driven.
On MDF screws the recess is cut into the cone after the head is finished, so the depth is taken from a finished surface. On a small countersunk head there is very little material between the bottom of the recess and the cone, and a recess that is too deep breaks through.
What decides whether these small stainless screws pass is the cone, the patch boundary and the way the head sits in a real board. The inspection agreement covers those, and the criteria come from the drawing.
Cone and patch on the projector |
Thread and start checked |
Material checked |
Salt-spray testing where plated |
On MDF screws the cone is measured for diameter and included angle, and the underside junction is checked for a radius. A cone that measures correct but carries a radius seats high, which on a flush joint is the same as a wrong angle.
The patch is measured for its distance from the head and for its length along the thread. Removing the running torque is not the aim here; the aim is a patch that starts clear of the cone and covers the thread that engages.
Flushness is checked by driving a sample into a board of the customer’s thickness at the intended torque. That test brings the screw, the countersink and the board together, and it is the only one that predicts how the joint will look.
Every batch of MDF screws is traceable to the wire or bar it was made from and to the passivation lot that finished it. The grade and heat number appear on the material certificate supplied with the parts, and the patch material and torque results are recorded with the batch.
ISO 9001:2015 |
RoHS test report |
Registered trademark |
Patent: security screw and driver |
With each shipment we supply the material certificate, the inspection record for the dimensions on the drawing, including the cone and the patch position, and the passivation record. The records carry the drawing revision and the batch number, so a repeat order of MDF screws seats flush the same way.
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 these small stainless screws the first article is driven into the customer’s board, because flushness only exists in the joint. 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
|
Repeat orders of MDF screws are checked against the same first article, so a flush seat proved once is reproduced. Buyers and quality engineers visit for sample review, process discussion and supplier audits; the visit is arranged around production so the cone turning and the patch station 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 |
Usually the cone angle does not match the countersink, or the patch has run up to the head and is acting as a spacer.
The countersink in the board has crushed. MDF is soft, so the driver has to stop at a clutch setting rather than at a feel.
Into a board directly, yes. A fine thread in MDF tears the fibre instead of cutting it, and a pilot hole controls where it goes.
It adds interference on the thread so the screw resists backing out in a joint that is opened and closed.
It must not. Nylon on the cone lifts the head off the countersink, and the fixing is no longer flush.
Head diameter and cone angle, recess size, thread and pitch, length under the head, patch position and the board thickness.
How an MDF screw project runs from drawing to repeat delivery:
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1
Send the drawing, the board and the countersink
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→ |
2
Cone angle and patch agreed
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→ |
3
First article driven flush into your board
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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 cone angle, recess size, thread and pitch, length under the head, patch position, and the board thickness and countersink.
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Head diameter
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Cone angle
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Recess
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Thread
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Patch position
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Board thickness
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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
