DIN 6912 Low Head Socket Screws with Pilot
In compact mechanical builds, failures often start at the first two turns—misalignment, side-load on the driver, and cross-threading into tapped holes. A pilot tip changes the entry condition: it guides the screw through the top component, stabilizes coaxiality, and only then allows the thread to engage. That reduces rework and helps the joint reach target preload without hidden thread damage that later shows up as loosening, fretting, or leakage.
When head clearance is limited, DIN 6912 low head socket screws offer a controlled low-profile head geometry, while the pilot feature is defined by drawing to match your stack-up and hole strategy (clearance pilot vs lead-in pilot).
- Guide entry before threading
- Cut cross-threading incidents
- Improve torque-to-preload repeatability
- Fit low axial clearances
- Specify pilot fit by intent
- Customize pilot length per stack
Technical Specifications
Product Name
Low Head Socket Screws with Pilot / Pilot Tip Low Profile Socket Screws
Standards
DIN 6912 (metric low head hex socket screw); pilot feature per drawing (dp/lp tolerances defined by fit intent)
Material
Alloy steel (e.g., SCM435 / 42CrMo4 equivalent), Stainless steel A2 / A4, 17-4PH (request-based)
Diameter Range
Typical metric: M3–M20 (program-dependent); other sizes by print
Grades
10.9 / 12.9 (per ISO 898-1 for Q&T alloy steel); A2-70 / A4-80 (per ISO 3506-1 for stainless)
Surface Finish
Black oxide, zinc plated, zinc-nickel, phosphate/oil, inorganic zinc flake; stainless passivation
Certifications
ISO 9001; EN 10204 3.1 material cert; RoHS/REACH on request; PPAP support for program builds
1: Cross-threading into tapped holes (blind holes, limited access)
What happens in assembly: The driver approaches at a slight angle; the thread starts immediately; the first threads in the female part get damaged, and torque rises early (false “tight”).
Pilot solution: A non-threaded pilot enters first and forces alignment before thread engagement, reducing the cross-threading chain and improving first-pass yield.
2: Clearance-hole float causes side-loading and torque scatter
Root cause: When the top plate has clearance, the screw can tilt until threads catch. That side-load increases friction scatter, so torque becomes a poor proxy for preload.
Pilot solution: A pilot sized to the top clearance hole acts as a temporary locator, stabilizing the axis and improving torque-to-preload repeatability.
3: Preload relaxation from embedding (low head seating area)
Engineering reality: Low head designs reduce head height; depending on head diameter and seating conditions, bearing pressure can increase on softer surfaces.
Fix: Use hardened flat washers, control counterbore flatness, and avoid seating on burrs/paint ridges.
4: Mixed materials = galvanic + seizure risks
Stainless into aluminum can corrode/seize; stainless-on-stainless can gall.
Fix: Choose A4-80 for chloride exposure, apply anti-seize where galling risk exists, and define lubrication in the assembly spec.
Pilot intent must be specified (two common cases):
Clearance pilot (through-hole locating): dp matched to ISO 273 clearance series.
Lead-in pilot (anti cross-thread): dp below internal thread minor diameter to guide entry without cutting.
This is a dimension example for “DIN 6912 dimensions” search intent.
DIN 6912 controls the low head geometry, while the pilot is per drawing.
| Thread (d) | Pitch (P) mm | Hex socket (s) mm | Head height (k) mm | Thread length (b)* mm | Pilot Ø (dp) mm | Pilot length (lp) mm |
|---|---|---|---|---|---|---|
| M4 | 0.7 | (DIN 6912) | (DIN 6912) | (DIN practice) | 4.8–5.0 | 2–6 |
| M5 | 0.8 | (DIN 6912) | (DIN 6912) | (DIN practice) | 5.8–6.0 | 2–8 |
| M6 | 1.0 | (DIN 6912) | (DIN 6912) | (DIN practice) | 6.4–6.6 | 3–10 |
| M8 | 1.25 | (DIN 6912) | (DIN 6912) | (DIN practice) | 8.4–8.6 | 3–12 |
| M10 | 1.5 | (DIN 6912) | (DIN 6912) | (DIN practice) | 10.5–10.8 | 4–15 |
* Note: For production pages, we normally publish the exact DIN 6912 s/k/dk limits from the standard and list pilot as “per drawing”. If you want me to lock the exact numeric s/k/dk values, paste your size list (e.g., M4–M10) or your internal drawing table.
1) Hole Clearance (ISO 273) + pilot fit
Pick clearance series per ISO 273 (fine/medium/coarse). Then define pilot dp with a realistic fit strategy.
Avoid: tight pilot + punched coarse hole → jamming, false torque, damaged seating.
2) Torque & Preload: control lubrication
Torque is friction-sensitive. Changing from dry to oiled can materially change preload at the same torque.
Practical control: define assembly condition (dry / light oil / anti-seize) and validate on the real joint stack-up with torque-tension testing for critical joints.
3) Washers under low head screws
Use hardened washers when the seating surface is aluminum, coated, or you require stable preload after cycling. It reduces embedding and preload loss.
4) Counterbore depth / seating flatness
Low head screws have less “forgiveness” for counterbore errors. Control depth and deburr; don’t seat on a burr ring.
5) Thread engagement and stripping prevention
In aluminum/castings, increase engagement length or specify inserts for high service cycles. In steel, confirm engagement against required clamp and safety factors.
Related Products
FAQ
What is DIN 6912 used for?
DIN 6912 specifies metric low head hex socket screws used when axial head clearance is limited.
It defines head geometry and drive interface so designers can control fit in compact assemblies.
What’s the difference between DIN 6912 and standard socket head cap screws (ISO 4762)?
DIN 6912 has a reduced head height to improve clearance, while ISO 4762 uses a standard head with more drive depth and head margin.
Choose DIN 6912 for tight envelopes; choose ISO 4762 when torque capacity and robustness are priority.
What does a pilot tip do on a low head socket screw?
A pilot tip guides alignment before the thread engages, reducing cross-threading and improving assembly repeatability.
It’s most useful in floating stacks, blind tapped holes, and automation fixtures.
How do I size the pilot diameter (dp)?
Size dp based on fit intent—either matched to the top clearance hole (locating) or below the tapped hole minor diameter (lead-in).
If the top hole follows ISO 273, dp should be selected to avoid jamming under realistic hole tolerances.
Do I need washers with DIN 6912 low head screws?
In many joints, yes—especially on aluminum or coated surfaces.
Washers reduce embedding, protect the seating surface, and help maintain preload after thermal or vibration cycling.