What is the difference between DIN 7504 types K, N, O and P?

K commonly denotes a hex washer head and N a pan head. O/P are countersunk designations used across different editions and commercial catalogs; P must not be described as a truss or wafer head. ISO 15482 covers flat countersunk heads and ISO 15483 raised countersunk heads. Confirm the drawing, edition, drive and dimensions before substituting a designation.

How do DIN 7504 ST sizes map to IFI numbers?

Approximate mapping: ST2.9≈#4, ST3.5≈#6, ST3.9≈#7, ST4.2≈#8, ST4.8≈#10, ST5.5≈#12, ST6.3≈#14. Note this is approximate — the standards differ in tolerances, test methods, and material requirements, so export orders must follow the target market's standard.

What does DIN 7504 require of the drill point?

The screw drawing and applicable product/mechanical standard determine the required point geometry and test conditions. A DIN purchasing designation alone is not a die drawing. Obtain the required point drawing and test conditions before ordering tooling.

Which dies do I need to produce DIN 7504 screws?

Use the customer-confirmed catalog to check screw size, drill diameter, flute length and available style. ST size or plate thickness alone does not determine an L-series. Compare HSS and carbide against the actual wire and forming process.

DIN 7504 Self-Drilling Screws — K/N/O/P Spec Guide for Die Manufacturers

Understanding the DIN 7504 Standard Family

DIN 7504 is a withdrawn German standard for self-drilling screws with tapping screw threads. The designations below are common purchasing references; their edition and the approved drawing must be checked before deriving product or die requirements.

Standards note: DIN 7504 has been formally superseded by ISO 10666, ISO 15480, ISO 15481, ISO 15482, and ISO 15483. However, DIN 7504 designations (particularly DIN 7504-K) remain the most widely used commercial references in European, Middle Eastern, and many Asian markets. This guide uses DIN 7504 terminology because it is what most buyers and suppliers still reference in practice.

DIN 7504 Types at a Glance

Standard	Head Type	Drive	Primary Application
DIN 7504-K	Hex washer head	External hexagon	Metal roofing, cladding, general steel
DIN 7504-N	Pan head	Phillips/Pozidrive	Sheet metal assembly, HVAC, enclosures
DIN 7504-O	Countersunk head	Phillips/Pozidrive	Flush-mount applications, trim panels
DIN 7504-P	Flat countersunk head	Phillips/Pozidrive	Flush seating; confirm drawing and ISO 15482 edition

Size Designations and Dimensions

ST identifies a tapping-screw thread size. Use the specified standard edition and screw drawing for thread pitch, root diameter and tolerances. The following nominal size correspondence is approximate and does not establish interchangeability.

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

Drill Point Requirements per DIN 7504

The finished-screw drawing defines the drilling section and the transition to the thread. A purchasing head designation is not a pointing-die drawing; obtain the required geometry before ordering tooling.

Point Length (per DIN 7504)

Measure the drill section and the thread-free region as defined on the drawing. For a multilayer assembly, include material thicknesses and gaps when verifying that the point clears the stack before threads engage. Drilling capacity belongs to the tested fastener, not a universal point-length multiplier.

Drill Diameter (per DIN 7504)

Distinguish nominal thread diameter, unthreaded blank diameter, drill diameter and thread root diameter. Use the required drilled-hole and thread-engagement design together with the approved point drawing; the ZLD catalog below lists available drill diameters, not normative DIN limits.

Flute Geometry

Specify flute length, width, depth and web geometry on the drawing
Define point angle and any edge or split-point features explicitly
Agree symmetry, datum and runout measurement methods
Test chip clearance and drilling performance on the actual rated substrate

Mapping DIN 7504 to ZLD Die Series

ST Size	Drill Ø Range	ZLD Die Series	Die Codes
ST 2.9	2.2–2.4 mm	L1–L2	L1-22, L1-23, L1-24
ST 3.5	2.7–2.9 mm	L1–L3	L1-27, L1-28, L1-29
ST 3.9	3.0–3.2 mm	L1–L3	L1-30, L1-31, L1-32
ST 4.2	3.3–3.6 mm	L1–L4	L1-33, L1-34, L1-35, L1-36
ST 4.8	3.7–4.2 mm	L1–L5	L1-37, L1-38, L1-39, L1-40, L1-41, L1-42
ST 5.5	4.3–5.1 mm	L1–L7	L1-43, L1-44, L1-45, L1-46, L1-47, L1-48, L1-49, L1-50, L1-51
ST 6.3	5.3–5.7 mm	L1–L7	L1-53, L1-54, L1-55, L1-56, L1-57

Testing Requirements

Use the mechanical-performance standard and edition specified by the customer. Record the fastener construction and specimen condition so drilling and torsion results can be compared with the applicable acceptance criteria.

Drilling Performance Test (per DIN 7504)

Agree the plate material and thickness, fixture, driver speed, axial force, timing and failure criteria from the specified test method. Keep those conditions consistent when comparing production samples and retain the actual results.

Torsional Strength Test (per DIN 7504)

Use the specified torsional test fixture and failure definition. Record failure torque and location, and compare with the applicable fastener requirement. The die series does not supply a universal minimum torsional value.

DIN 7504 vs IFI: Key Differences

An ST/# size correspondence is a procurement aid. DIN/ISO product and mechanical standards and the North American standard named by the customer may differ in dimensions, material rules and test conditions. IFI is an industry organization; obtain the specific required document and edition rather than treating “IFI” as one interchangeable standard.

Source DIN 7504-Compatible Dies

ZLD Precision Mold manufactures drill point dies compatible with all DIN 7504 types. Our L1–L7 series covers the complete ST 2.9 through ST 6.3 range — check the specification table for the size and geometry that matches your screw standard.

View our specification table | Request DIN 7504 dies