Drill Point Die Selection Guide: Five Steps to the Right Series, Style and Material

Selecting a drill point die requires two linked decisions: defining a screw that works in the intended joint, and choosing tooling that reproduces its point reliably. Keep installation tests separate from factory forming trials. A screw that stalls does not, by itself, prove that the die series is wrong.

Use the following five steps to prepare a tooling enquiry. Bring the approved drawing where available, and record which dimensions or process conditions still need confirmation.

Step 1: Confirm the screw specification and drawing

Record the product standard, edition, head form, thread size and acceptance requirements agreed with the customer. IFI and DIN are standards organizations; an IFI size number or a DIN reference without the document and edition is not a complete product specification.

The ZLD catalog uses this approximate size cross-reference:

IFI size	#4	#6	#7	#8	#10	#12	#14
Approximate DIN size	ST2.9	ST3.5	ST3.9	ST4.2	ST4.8	ST5.5	ST6.3

These references are not interchangeable specifications. Confirm the actual thread and point dimensions against the order. In this table, #7 corresponds approximately to ST3.9. The available catalog range also does not define the entire scope of any standard.

Step 2: Match the point geometry to available L-series codes

Compare the approved point drawing with the catalog column for screw size and Dø. Examine flute length, cross-section, web, cutting edges and transitions. L1–L7 are ZLD geometry families, not standardized drilling-thickness ratings.

Series	Available screw sizes	Catalog comparison
L1–L2	#4, #6, #7, #8, #10, #12, #14	Compare each code’s flute length; the two series share sizes
L3	#6, #7, #8, #10, #12, #14	Check the different point profile against the drawing
L4	#8, #10, #12, #14	Confirm the size-specific style as well as length
L5	#10, #12, #14	Check the MB/MC change between sizes
L6–L7	#12, #14	Dø 4.3–5.1 and 5.3–5.7 mm; no 5.2 mm column

Substrate grades, layer thicknesses, gaps and installation settings belong in the finished-screw test. Verify that drilling and thread engagement occur as intended. A longer flute is not proof of greater drilling capacity, and point length alone does not establish blank volume or forming force.

Step 3: Check die style and machine fit

Style and size must be read together with the series. L1/L2 offer MA/MB for #4–#12 and L3 for #6–#12; all three use MB at #14. L4 uses MB for #8–#12 and MC for #14; L5 uses MB for #10 and MC for #12/#14. L6 and L7 use MC.

MA (I), MB (II) and MC (III) identify tool styles, not screw head types. Confirm the actual body dimensions, support surfaces, orientation, clamping and machine-pocket drawing. Two dies with the same style name are not automatically interchangeable on every machine.

Send the machine model and a measured drawing of the current tool if the pocket specification is unavailable. Check the matched pair together during setup.

Step 4: Compare tool materials under actual forming conditions

Both HSS and tungsten carbide can be candidates. Identify the wire actually contacting the die, including grade, delivery condition, surface and lubrication. For a bimetal screw, distinguish the formed point material from the body material and confirm the production route.

Input	What to compare
Wire condition	Composition, annealing condition, dimensions and lot consistency
Damage mechanism	Abrasive wear, pickup, chipping or fracture, with photographs and measurements
HSS candidate	Exact steel, heat treatment and supported edge geometry
Carbide candidate	Complete supplier grade, WC structure, binder and comparable test data
Trial outcome	Accepted screws, dimensional stability, downtime and reconditioning cost

For 304 or 316 wire, work hardening and adhesion may affect forming. Neither grade alone mandates carbide or a particular coating. Hold wire, geometry, alignment and inspection criteria constant when comparing tools, and calculate cost per accepted screw.

Step 5: Evaluate a coating against a measured problem

A PVD coating is optional. First establish the failure mechanism and correct inadequate support, alignment or lubrication. TiN, TiAlN, CrN or AlCrN may be discussed with the coating supplier, but the name alone does not establish suitability or a life improvement.

Check	Evidence to obtain
Substrate compatibility	Deposition conditions compatible with the tool grade and heat treatment
Surface and edge preparation	Agreed roughness, edge condition and cleaning process
Dimensions and adhesion	Coating allowance, cavity measurements and an appropriate adhesion check
Production comparison	Coated and uncoated tools under comparable conditions, with the same removal criterion

Compare total processing cost and accepted output. A coating cannot repair an unsuitable point drawing or compensate for an overloaded or misaligned tool.

Include the wire and blank in the enquiry

Blank diameter, length and profile together determine the volume available for forming. Check filling, flash, folds and cracking with the actual wire lot. Tensile properties and reduction of area provide useful material information, but do not alone predict the result of a particular cavity and process.

Dø, point width and wire diameter are separate dimensions. Use the appropriate populated catalog row and the approved blank drawing; do not interpolate an empty wire cell. See the wire properties guide for the information to request.

Catalog or custom tooling?

Catalog codes provide a starting geometry. Confirm the exact dimensions, tolerances and machine interface before ordering. Custom work may involve a different point profile, diameter, tool body or reproduction of an existing set.

For reproduction, provide the drawing and samples where possible. A worn die shows the current condition, so reconstructing original dimensions requires measurement and agreement rather than copying wear. Standard samples typically take 3–4 working days; confirm the schedule for the actual order.

Investigate symptoms before changing the series

Observation	Checks to make
Finished screw stalls	Point geometry and damage, substrate stack, speed, axial load and thread engagement
Formed point is off-centre	Matched pair, alignment, blank positioning and cavity filling
Die edge chips	Support, overload, wire condition, tool grade and prior damage
Material adheres to the die	Wire surface, lubricant delivery, cavity finish and coating condition
Dimensions drift	Wear, buildup, temperature, fixture movement and measurement method
Tool does not fit	Body drawing, pocket, orientation and clamping

Record the stage at which damage first appears. A finished screw’s drilling failure and a die’s forming failure require different evidence. Agree replacement limits from dimensional and production results.

What to send with an RFQ

Send the screw and point drawing, size and Dø, current die or sample photographs, machine-pocket information, wire grade and condition, approximate production volume and the observed problem. Identify the intended joint and drilling test separately.

A sample or photo can start the discussion when drawings are incomplete. It does not replace dimensional confirmation before manufacture. The die selector lists catalog candidates from size and exact Dø; it does not automatically approve a material, coating or installation capacity.

From selection to a trial order

Confirm the drawing and catalog code, verify machine fit, compare material and optional coating in forming trials, then validate finished screws for their intended use. Keep the trial results with the tool and wire lot records.

Zhonglianda supplies L1–L7 tooling in HSS and tungsten carbide. Trial orders can start with one matched set. Send the drawing or sample details to confirm the specification and quotation.

Further reading

• What is a drill point die?
• IFI and DIN size references
• Carbide and HSS comparison
• PVD coatings
• Common die problems