L6 Series Drill Point Dies: Long-Point Tooling for Self-Drilling Fasteners
L6 dies for #12/#14: Dø 4.3–5.1 and 5.3–5.7 mm, flutes 15.8–17.0 mm and MC. Match drawings and validate forming and finished screws separately.
L6: Long-Flute Geometry in the Catalog
L6 is available for #12 and #14 screws. The catalog lists Dø 4.3–5.1 mm for #12 and 5.3–5.7 mm for #14; there is no 5.2 mm column. Flute lengths are 15.8–17.0 mm depending on Dø, and the die style is MC (III). ST5.5 and ST6.3 are approximate size references, not proof that two finished-screw specifications are interchangeable.
Choose the code that matches the approved point drawing and machine pocket. A forming trial checks whether the die reproduces that geometry with the actual wire and machine. A separate finished-screw test checks drilling and the intended joint. L7 offers a longer flute range, so L6 is not the largest series or a universal maximum-capacity tool.
HSS and tungsten carbide are possible die materials. Assess their grades against the forming duty and accepted output rather than choosing from installed plate thickness or an industry label.
What the Longer Point Requires
Material Removal During Installation
The finished screw cuts the substrate and moves chips through its flutes. The removed volume depends on the hole profile and the actual layers, including their grades and thicknesses. Check chip evacuation and the transition to thread engagement in the specified installation test.
The production die performs a different operation: it plastically deforms a wire blank. Installation chips do not pass through its cavity. Die loading must be assessed from blank condition, cavity geometry, friction and machine motion.
Cutting Time and Heat
Measure drilling time under defined speed, axial load and material conditions. A stalled screw can have several causes, including point damage, unsuitable geometry or mounting conditions; time alone does not diagnose die wear.
The screw's material and heat treatment govern its response during drilling. Monitor die temperature separately during forming. Do not transfer the installation temperature to the tool or infer a temperature limit from L6.
Point Geometry and Cavity Filling
Compare the complete point profile: flute length and cross-section, web, cutting edges, transition radii and thread start. The catalog length does not specify a progressive flute, reinforced web, split point or particular rake angle for every L6 code.
During setup, examine filling, flash, cracking and symmetry. Determine blank volume from the whole profile and forming route. A deeper flute alone does not imply more material or a higher forming force.
Specifications at a Glance
| Parameter | L6 catalog data |
|---|---|
| Screw sizes | #12 and #14 |
| Approximate DIN size references | ST5.5 and ST6.3 |
| Dø for #12 | 4.3–5.1 mm |
| Dø for #14 | 5.3–5.7 mm |
| Flute length ℓ | 15.8–17.0 mm (17.0 mm catalog reference) |
| Die style | MC (III) |
| Available codes | L6-43–L6-51 and L6-53–L6-57 |
| Die materials | HSS or tungsten carbide, grade evaluated in forming trials |
The catalog entry is 15.8–17.0(17.0): retain the parenthetical value as a catalog reference, and use the agreed code drawing for the required dimension and tolerance. Confirm the exact column, die-body drawing and mating pair. Dø, point width and wire diameter are different dimensions. Use the populated row for the relevant thread form and the approved blank drawing; an empty wire cell does not approve an interpolated value. Finished-product standards, their editions and acceptance tests are agreed separately.
Comparing HSS and Tungsten Carbide
Record whether the observed tool damage is uniform wear, material pickup, edge chipping or fracture. Compare candidate grades under the same wire condition, alignment, lubrication and replacement criterion. Changing material will not correct a poorly supported edge or a misaligned holder.
For HSS, confirm the exact steel and heat treatment. For carbide, evaluate the complete grade rather than a binder percentage alone. The information below supports comparison without prescribing a composition for L6.
Material Information to Compare
| Information | What it helps establish |
|---|---|
| Grade, manufacturer and delivery condition | Traceability and the material actually supplied |
| WC grain and binder composition | The complete carbide structure, considered with measured properties |
| Hardness and test method | Comparable supplier data, not a universal series limit |
| Fracture and wear results | Behaviour of the supported geometry under the real load |
| Optional PVD process | Substrate compatibility, adhesion and dimensional allowance |
Measure accepted screws per matched pair and include rejects, changes, regrinding and coating in the cost. A coating is a candidate only when its process is compatible and a comparative trial supports its use.
Application Requirements to Clarify
Multi-Layer Structural Connections
Document every layer, its material, thickness and any gaps, together with required thread engagement and connection loads. Test the finished screw in that stack; total thickness alone does not choose an L6 code.
If the design proposes removing a pilot hole or replacing a bolt, the connection designer must approve the fastener and verify its capacity. Only after that decision should the point drawing be matched to tooling.
Heavy Steel Building Primary Frames
Main-frame connections require a specific structural design and suitable fastening system. Do not assume a long self-drilling point is an alternative to a load-bearing bolt. Review the selected screw's permitted use, layout, edge distances and applicable performance evidence with the designer.
For an approved screw, the die supplier needs its point drawing, not simply the description “primary frame.” Tooling controls the formed geometry; it does not provide the connection approval.
Heavy Industrial and Transport Equipment
For equipment panels, brackets and subassemblies, identify cyclic loads, vibration, corrosion, access and inspection needs. Check point penetration, thread engagement and the finished joint against those requirements.
Translate the approved screw geometry into the die and blank drawings. The name of the transport or industrial sector neither mandates L6 nor determines carbide or a coating.
Renewable Energy Structures
Solar and wind systems can involve different materials, coatings, environmental loads and maintenance arrangements. Agree the fastener and tests with the system designer, including corrosion compatibility and the intended installation conditions.
If its approved point matches an L6 column, validate machine fit and forming performance. A renewable-energy application does not itself establish a market share, material recipe or structural qualification for L6.
Production Checks for L6 Dies
1. Confirm Machine Capacity
Confirm permitted force, stroke, rigidity, clamping and operating cycle with the machine manufacturer. Measure load, filling and symmetry during setup with the actual wire. Use the tool drawing to verify support and pocket fit, even if the machine already produces another #12 or #14 screw.
2. Verify Wire Quality
Agree composition, delivery or annealed condition, diameter, surface and cleanliness with the wire supplier. Set sampling and test methods according to supplier capability and defect risk. Associate each wire lot with production results; do not infer blank diameter from Dø.
3. Evaluate Blank Preparation
Where the machine permits preforming, compare the route with and without that step. Measure material distribution, final load, filling, accepted output and total cost. An additional operation can help or add variation; its benefit must be demonstrated for the actual profile.
4. Control Lubrication and Temperature
Check delivery to both die halves and compatibility with forming, cleaning and subsequent coating. Define measurement location and method before setting thermal limits. Infrared readings require appropriate emissivity and do not necessarily represent contact temperature. Adjust cooling with the machine and fluid suppliers.
5. Record Production Results
Track matched pair, orientation, wire lot, machine settings, accepted count, critical dimensions and removal reason. Connect those records with separate drilling tests of finished screws. They support fault analysis and replacement planning; they do not by themselves certify the product.
Choosing and Validating an L6 Tool
L6 provides 15.8–17.0 mm flute geometry in MC for #12/#14, with separate Dø ranges. Select by drawing and catalog column, then validate the real forming process. Evaluate HSS, carbide and optional coatings through comparable trials and accepted-piece cost.
Send the drawing, sample, wire condition and machine-pocket information when discussing a trial pair. Include the intended joint and finished-screw test conditions as separate product requirements. View the catalog or consult our engineers to prepare the trial.
WHEN YOU ARE READY
Get a Die Recommendation for Your Screw
Share your screw size, drawing, sample photo, or drilling thickness. Our engineering team can help identify the relevant drill-point die specification before quotation.