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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:M5 Screw
Materials:Carbon Steel
Surface treatment:Eco White Zinc Plated
Head Type:Cylindrical socket head
Drive:Allen hex socket
Thread:M5 machine thread
Point:Plain, chamfered
Forming:Formed and threaded; plating applied last
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10
We make M5 screws in carbon steel with an eco white zinc plate, a socket head and a hex key drive, quoted to the drawing. M5 is the smallest size that still carries a bracket while fitting a compact enclosure, and the 4 mm socket and the engagement are agreed first.
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.
An M5 screw is a metric machine screw with a 5 mm nominal thread, made on this page in the socket head cap form with a hex key drive. The part recorded here is carbon steel with an eco white zinc plate, quoted with the length made to the drawing.
5 mm thread. The smallest metric size that still behaves like hardware rather than like a fitting.
Socket head. A cylindrical head with a hexagon inside, driven with a 4 mm key on this size.
Eco white zinc. A trivalent zinc plate that gives sacrificial protection and a bright finish.
They are used in small equipment, enclosures and brackets, where a joint has to carry a real load but the space is tight. An M5 screw is often the item that decides whether a design closes: it is the last size that fits a compact counterbore and the first that holds a bracket without a washer.
M5 is where the socket head cap screw stops being a small fitting and starts being a structural fixing. Below it, the socket and the head are small enough that the drive limits what the joint can be tightened to; above it, the head and the washer footprint no longer fit inside a compact enclosure. M5 sits between those two limits, and that is why so many bracket and cover joints land on it.
The key is the reason the boundary is sharp. An M5 socket takes a 4 mm key, which is small enough that a worn or cheap key rounds the hexagon before the joint reaches its preload. An M6 takes a 5 mm key that is far more forgiving. So on M5 screws the key becomes a working tool that has to be maintained, not an accessory.
The head is the second half of the trade. An M5 cap head is around 8.5 mm across, which fits inside a small enclosure but gives a bearing face that is still modest on a thin panel. Where the panel is thin, the joint benefits from a washer or a washer head more than from a larger screw.
The thread is the third. An M5 thread carries a bracket or a mount comfortably when the engagement is adequate, and in a thin plate the engagement is what decides the joint. The screw’s diameter is rarely the limit at this size; the part it goes into usually is.
Eco white zinc completes the picture. It protects a carbon steel screw at a lower cost than stainless, and it is the standard finish on equipment hardware that is not exposed to washing or salt. The plate is thin enough that the socket still takes its key, which is checked on a sample after plating.
The part is quoted to the drawing with the thread, the head and the engagement stated separately. Custom lengths up to 2,000 mm, subject to DFM review after drawing submission. The quotation for an M5 screw carries the length, the head and socket, the thread, the standard it follows, and the engagement in the mating part.
| Item | How it is defined | What we control |
|---|---|---|
| Thread | M5 machine thread | Pitch, length and start |
| Head | Cylindrical socket head | Diameter, height and bearing face |
| Socket | Hexagon in the head | Across flats and depth |
| Standard | DIN 912 family | Dimensions and tolerances |
| Engagement | In the customer part | Thread depth agreed |
| Plate | Eco white zinc | Thickness and socket fit |
The standard matters on M5 screws because M5 cap screws are made to several dimensional families that differ in head size and socket depth. A screw made to one family will not be interchangeable with another in a counterbore that was made for the first.
On M5 screws the engagement is the customer’s dimension. On a bracket joint it is usually generous; on a thin panel it is short, and that is where the joint fails rather than at the screw.
On M5 screws the length is measured under the head, and it has to be chosen so the thread engages fully without bottoming in a blind hole. On M5 the step from one length to the next is often enough to change a joint from solid to bottomed.
Four properties decide M5 screws of this form, and each one carries a cost:
| Property | What it gives | What it costs |
|---|---|---|
| 5 mm thread | Carries brackets and mounts | No reserve in a thin plate |
| 4 mm socket | Fits inside a small enclosure | Key wear rounds the hexagon early |
| Compact head | Fits a small counterbore | Modest bearing face on thin panels |
| Eco white zinc | Protection at low cost | Not for washing or salt |
The value of M5 screws is a size that fits where M6 will not and carries where M3 cannot. On compact equipment that is the whole point: it is the only size that satisfies both the space and the load.
The cost is the margin. At M5 the key is small and the head is small, so a worn tool or a thin panel turns a correct screw into a failing joint faster than at M6.
The recorded finish is eco white zinc, a trivalent zinc plate with a bright passivation. On carbon steel it gives sacrificial protection and a clean appearance, and it is the usual finish on indoor equipment hardware.
| Option | How it protects | Effect on socket and head | Typical use |
|---|---|---|---|
| Eco white zinc | Trivalent zinc, bright | Build; socket re-checked | Indoor equipment hardware |
| Clear zinc | Sacrificial zinc, thinner | Less build; socket closer to size | Indoor assemblies |
| Zinc nickel | Higher corrosion resistance | Build; socket gauged after | Damp and industrial |
| Black oxide | Conversion film, oiled | No measurable build | Dark mechanisms |
| Stainless, passivated | Passive film, no coating | No build; different strength | Wet and food areas |
On M5 screws the socket is a tight fit once plated: a layer a few microns thick reduces the across-flats, and a key that fitted before plating may become tight. The socket on this size is therefore checked with the key after plating rather than only gauged.
On the head face the plate is thin enough to leave the bearing surface flat, but on a panel joint the coating is also the surface that touches the paint. A soft zinc layer can mark a finished panel, which is why the head is checked for face quality as well as for size.
Three assemblies where the space is small and the load is real:
| Where it sits | The screw holds a bracket or a plate inside a housing where an M6 head would not fit. |
| When it goes wrong | The socket rounds out during assembly, or the panel marks at the head. |
| Why it happens | The key is worn, and the plate is thin under the head. |
| What we control | Socket proved with the customer key; first article assembled in the housing. |
| Where it sits | The screw fixes a bracket to a frame where the joint carries the weight of a component. |
| When it goes wrong | The joint loosens, or the thread pulls out of a thin plate. |
| Why it happens | The engagement is short, and the torque is set by feel. |
| What we control | Engagement and torque checked; first article loaded after assembly. |
| Where it sits | The screw closes a panel onto a frame where several fixings share the load. |
| When it goes wrong | The finish marks at the heads, or a fixing strips. |
| Why it happens | The bearing face is small for the panel, and the plate is bright but soft. |
| What we control | Head face and plate checked; first article assembled on the finished panel. |
Four reasons that matter on M5 screws, where the margin is small, each tied to something the drawing or the first article proves. All four show in the sample.
|
Standard and engagement stated
The drawing states the dimensional family and the engagement, because M5 cap screws are made in several that are not interchangeable. Basis: Standard and engagement agreed. |
Socket cut, then plated and checked
The socket is cut in a finished head and checked with the key after plating, because on a 4 mm socket the plate matters. Basis: Socket checked after plate. |
|
Key and torque tool used
The first article is tightened with the customer key and torque setting, because a small socket only gives what the tool asks. Basis: Torque proved with the tool. |
Same limits on repeat runs
Standard, socket and thread are recorded with the drawing revision, so a repeat batch takes the same setting. Basis: Same limits across orders. |
These screws are formed and threaded from carbon steel wire, with the cylindrical head formed and faced, the hexagon broached and the thread rolled; the parts are then white zinc plated. The first piece of every run is measured on head diameter and height, socket across flats and depth, thread and length.
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The socket is the feature with the least margin on M5 screws. It is broached after the head is faced, and the depth has to leave a section under the hexagon that can take the key load; a socket cut a fraction deep distorts the head when the key is loaded, and one cut shallow stops the key engaging fully.
On M5 screws the head face is finished square to the thread, because it bears on the plate or the counterbore floor. On a panel joint the face is also what leaves the mark, so flatness is checked as a surface property rather than only as a dimension.
The thread is rolled, which gives a clean crest at this size, and the parts are then plated. The socket and the head face are checked again after plating, and a sample from each lot goes into the salt-spray chamber.
What decides whether an M5 screw passes is the socket, the head face and the thread. The inspection agreement covers those, and the criteria come from the drawing.
Head and socket on the projector |
Thread and start checked |
Core hardness checked |
Salt-spray testing of the white zinc |
On M5 screws the socket is measured across flats and for depth, and checked with the key on a sample from each batch. On a 4 mm socket a burr at one corner is enough to stop the key, so the check is done with the key rather than with a gauge alone.
The head is checked for diameter, height and flatness of the bearing face, and the face is inspected for marks that would telegraph through a painted panel.
The thread is gauged, and a sample is tightened to the stated torque in a test block at the customer’s plate thickness. That test shows whether the engagement is enough, which the screw’s own dimensions cannot tell.
Every batch of M5 screws is traceable to the wire it was made from and to the plating lot that finished it. The grade and heat number appear on the material certificate supplied with the parts, and the plating report carries the layer thickness and the lot number.
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 socket and head, and the plating report. The records carry the drawing revision and the batch number, so a repeat order of M5 screws takes the same setting.
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 size with little margin the first article is checked in the customer’s joint rather than on its own. Buyers visit during the process to review samples.
|
8,678+
customers served
|
87%
of orders from repeat customers
|
56%
of orders through referrals
|
89
countries and regions shipped to
|
Repeat orders of M5 screws are checked against the same first article, so the torque 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 heading cell 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 |
Because the head and the counterbore fit inside a compact enclosure. M6 gives more margin but needs more space.
The 4 mm key. A worn key rounds the socket before the joint reaches its preload, which is why the key is part of the process.
Yes. M5 cap screws are made in several dimensional families, and a head made to one will not fit a counterbore made for another.
Usually the engagement in the plate. In a thin plate the thread pulls out before the screw fails.
It protects carbon steel at low cost and suits indoor equipment. It is not the finish for washing or salt.
Length, head and socket, thread, the standard, the engagement in the mating part, and the finish.
How an M5 screw project runs from drawing to repeat delivery:
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1
Send the drawing and the mating part
|
→ |
2
Standard, socket and engagement agreed
|
→ |
3
First article tightened in the joint
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→ |
4
Batch production and repeat orders
|
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 length, head and socket, thread, the dimensional standard, the engagement in the mating part, and the finish.
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Length
|
Head and socket
|
Thread
|
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Standard
|
Engagement
|
Finish
|
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
