# Drill bit set Proline 78040K — metal bits Ø4 mm, length 75 mm, 2 pieces

**URL:** https://aio.lv/en/product--proline-78040k--11721329
**Data updated:** 2026-03-08 11:24 (EET)
**Category:** Drill Bits
**Manufacturer:** Proline
**Manufacturer code:** 78040K
**EAN:** 5903755153906
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 5.99 €
**Prices and availability valid until:** 2026-07-14 23:59
**Price without VAT (21%):** 4.95 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--proline-78040k--11721329

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 06.07.2026 | free |
| Pickup points | 09.07.2026 | 1.99 EUR |
| Courier delivery to door | 09.07.2026 | 4.99 EUR |

## Summary description

Proline 78040K drill bit set for metal includes two bits with 4 mm diameter and 75 mm overall length. Designed for drilling metal sheets, profiles and thin-walled materials, suitable for handheld drills and drill presses. Provides standard straight shank mounting and typical twist-drill geometry for general metalworking tasks and repair jobs.

## Long description

Proline 78040K drill bit set includes two HSS-Co metal twist drills with a 4 mm diameter and 75 mm overall length. These bits are manufactured by grinding for precise geometry and straightness, and they feature a 135° point angle with chamfering adjustment to enable fast, accurate starts and reduced walking during marking. Made from high-class high-speed steel with 5% cobalt, the bits resist high temperatures and are intended for demanding metalworking tasks on high-alloy steels, titanium, stainless and acid-resistant steels, creep-resisting steels, cast iron and other hard-to-machine materials. The straight shank fits handheld drills and drill presses for general repair and workshop use.
Advantages
The 135° point with chamfering adjustment shortens drilling time by improving centring and reducing the need for pilot holes. Cobalt-alloyed HSS construction increases heat resistance and wear life when cutting hard or abrasive metals. Precision grinding provides consistent diameter, straightness and hole accuracy. The standard straight shank ensures compatibility with common chucks on portable drills and bench machines.
Suitable for
 Drilling holes in stainless, acid-resistant and high-alloy steels
 Working with titanium and creep-resisting steels
 Repair and maintenance on metal sheets, profiles and thin-walled components
 Use in handheld electric drills and drill presses
Key specifications
 Diameter: 4 mm
 Overall length: 75 mm
 Material: high-speed steel with 5% cobalt (HSS-Co)
 Point angle: 135° with chamfering adjustment
 Manufacturing method: fully ground twist-drill geometry
 Shank type: straight shank compatible with standard chucks
How to use
Secure the drill bit in the chuck of a handheld drill or drill press, ensuring correct clamping of the straight shank to avoid slippage. Mark and centre-punch the drilling position to improve initial tracking. Use appropriate cutting fluid or coolant when machining stainless, high-alloy steels or other heat-sensitive materials to prolong bit life and maintain cutting performance. Apply steady feed pressure and moderate speed suitable for the workpiece material; reduce speed for harder alloys and increase coolant flow as needed.
Usage recommendations
For best results, start with a small pilot hole when drilling thick or highly hardened sections, keep sufficient coolant flow, and replace bits that show wear or chipping. Match drill speed and feed to the material: lower RPMs for harder alloys and higher RPMs for softer metals to optimize tool life and hole quality.

## Specifications

| Feature | Value |
|---|---|
| Length | 75 mm |
| Metal drill bits diameter | 4 |
| Number of drill bits | 2 pc(s) |

## FAQ

### How much does the Drill bits Proline 78040K Ø4 mm, 75 mm, 2 pcs cost, and is it available for purchase?

The price is 5.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 200 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 06.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All Proline products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized Proline service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

https://aio.lv/img/cache/product/11721329/67191787_large.webp