DIN 340 covers the long series of parallel-shank twist drills. Its role is to identify a length family; it is not a universal instruction for deep-hole drilling or a guarantee that a long drill will be stable in a particular setup. This guide explains the size fields to confirm, common ordering mistakes and how to approach a supplier with a complete requirement.
What does DIN 340 cover?
Choose a long series because access or depth requires it, then review the actual tool lengths and support. A longer drill changes the mechanical setup, chip path and available guidance. Keep reach past an obstruction separate from the length of the hole being drilled.
The reference used here is DIN 340:2006-11. Read the primary standard or manufacturer reference for the exact scope. For a purchase requiring formal conformance, identify the agreed edition and obtain the applicable standard and item drawing; the checklist below does not reproduce its complete dimensional tables.
Which sizes belong on the RFQ?
There is no single universal “DIN 340 drill size.” A standard identifies a defined family or feature, while the order still needs a selected diameter and the relevant geometry. Record each size using the symbols on the supplier’s drawing, because symbol conventions can differ between catalogs. Use millimetres for dimensional fields and state any angular requirement separately.
| Size or specification field | What to confirm |
|---|---|
| Diameter | Nominal cutting diameter and tolerance |
| Flute length | Length of the fluted section in the catalog drawing |
| Overall length | Complete tool length, in mm |
| Access distance | Distance from holder to entry surface |
| Full-diameter depth | Required bore depth, independently of access distance |
If a catalog provides several rows for one diameter, preserve the full item code and any form or length suffix. Do not select a nearby row solely because the diameter matches. A tool’s nominal size, manufacturing tolerance and the component’s finished-hole tolerance are different pieces of information.
A practical selection mistake to avoid
A part may have a shallow hole behind a raised fixture feature. A long drill can be needed for access even though the hole itself is not deep. State both distances on the inquiry. Otherwise a supplier may choose a long-flute tool where the actual need is a different reach envelope or a revised setup.
Who can supply DIN 340 tooling?
Gühring and Dormer Pramet offer drill catalog routes for length-series selection. Confirm the exact DIN designation on the quoted item; longer tools within a brand can also use manufacturer-specific dimensions.
Use the linked catalog as a starting point, then request the exact item drawing, construction, size row and standard edition from the seller. A manufacturer’s broad tool portfolio is not evidence that every diameter or form is stocked, or that a custom proposal automatically conforms to DIN 340.
Discuss a carbide alternative with KYTOOLS
KYTOOLS (Changzhou Kong Yun Precision Tools Co., Ltd.) publishes solid-carbide drill families and drawing-based tooling. If you are considering a carbide alternative or a special geometry, send the original standard requirement together with the part drawing and existing tool dimensions. Ask KYTOOLS to review the proposed construction and dimensional match before approval.
The published KYTOOLS catalog is the source for its listed models; this article does not declare those models compliant with every DIN number discussed. Keep any requirement for DIN 340 conformance, including form, edition and inspection documentation, explicit in the inquiry.
A useful quotation and approval checklist
- Attach the component drawing and, if available, the existing tool drawing or printed catalog code.
- State the workpiece material, hole condition and required dimensions with units and tolerances.
- Identify the machine, holder or taper connection and the coolant arrangement.
- Name the required standard edition and any permitted deviations; request written confirmation on the proposed drawing.
- Agree quantity, measurement method, marking, quotation validity and delivery destination.
When comparing a conventional standard tool and a drawing-based carbide alternative, qualify the proposed process as well as the purchase description. Keep the approved drawing and inspection record with the item code so a later reorder refers to the same configuration.
Send your drill specification to KYTOOLS, or download the drill catalog and inquiry template.