4 mm HSS M35 Cobalt Step Drill Bit with Seven Steps Total Length 75 mm Cylindrical Shank for Iron Steel and Stainless Steel
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The 4 mm step drill bit is designed for drilling precise holes in metal materials. It is made from HSS M35 high-speed steel with cobalt, suitable for drilling iron, standard steel, and stainless steel. The tip of the drill features seven small steps that gradually enlarge the hole to the full diameter. The spiral flute along the entire length of the working part removes chips from the hole. The 4 mm diameter is among the most commonly used sizes for installations, repairs, and locksmithing tasks.
The total length of the drill bit is 75 mm, with the working part featuring a spiral length of 42 mm. This allows for drilling sheets, profiles, and thicker metal parts. The cylindrical shank fits into a standard chuck of handheld drills, cordless drills, and bench drills. The diameter is marked on the shank, making it easy to distinguish the drill from others. The shape of the tip with steps is clearly visible in the detailed product photographs.
Compared to a standard spiral drill bit, this model features a tip composed of seven steps, whose diameter increases from the tip. The narrowest step creates a small pilot hole in the material, and each subsequent step enlarges it further. Thus, the hole is formed gradually in a single pass of the drill, without the need to pre-drill with a smaller bit. The photographs also show the traces of the individual steps on the wall of the drilled hole. This drill bit is intended for metal, particularly for iron, structural steel, and stainless steel.
- Type – step drill bit with spiral tip
- Diameter – 4 mm
- Working Part Length – 42 mm
- Total Length – 75 mm
- Material – high-speed steel HSS M35 with cobalt
- Tip – seven steps gradually transitioning to full diameter
- Shank – cylindrical
- Use – drilling into iron, steel, and stainless steel
- Package Contents – 1 piece of 4 mm step drill bit
When working with steel and stainless steel, use cutting oil or coolant to reduce the temperature of the tip and spiral. Adjust the speed according to the diameter of the drill bit and the hardness of the metal, hold the drill perpendicular to the surface, and apply only moderate pressure. After completing the work, clean the drill bit of chips and store it in a way that prevents the tip from touching other tools.
The 4 mm step drill bit is a useful tool for any workshop where metal drilling is required. The high-speed steel with cobalt makes it suitable even for stainless steel. The seven steps on the tip gradually enlarge the hole to the full diameter. The cylindrical shank ensures easy clamping into a standard drill. The package contains one drill bit with a diameter of 4 mm.
Delivery
Delivery to address€1.99
Estimated delivery: 23 November – 4 December
Shipped from China
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Returns and Exchanges
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Returns30 days to return without giving a reason
Withdrawal period30 days from receipt of the goods
Deadline to send the goods backWithin 14 days of withdrawing from the contract
Return shipping costsYou pay the postage for sending the goods back to Spain. With An Post (Standard Post), returning a parcel of up to 2 kg to Spain costs about €30. We charge no other fee.
RefundWithin 14 days of your notice of withdrawal, using the same payment method you used for the purchase. If you return the whole order, we will also refund the delivery cost.
Crediting of the amountUsually 2–10 working days, depending on the payment method
Product conditionYou may unpack the goods and try them as you would in a shop, and you can return them even without the original packaging
Returns addressQX-BOX AEMALL RETURN
Rotonda Rene Descartes, Parcela 101 – Nave 3
28070 Alcala de Henares, Madrid
SpainReturns centre in Spain operated by Qxbox, an e-commerce logistics provider and logistics partner of the sellers on our platform.
How do I return goods?
- Email us at info@lunzo.ie with your order number and the items you are returning.
- Pack the goods and send them by post to the returns address in Spain.
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Did the goods arrive damaged, do they not work, is something missing from the parcel or do they not match the description? We will sort it out.
Period for claiming a faultUp to six years from delivery of the goods
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- We will settle your claim within 30 days at the latest – with a new item, a price reduction or a refund.
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ExchangesA different size, colour or variant
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If the variant is available, we will send you instructions for the exchange. You pay the cost of sending the original item back; the new variant will be sent to you at no further charge.
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About the seller
This product is sold and shipped by an external seller. LUNZO guarantees you a safe purchase: online payments go through a secure payment gateway, and you handle your order, returns and complaints with us.
The following information has been provided by the product seller, who is responsible for its accuracy. The seller acts as a trader.
Seller:
Gansu Constar Technology Group Co., Ltd.
Address: No.10, Chuangxin South Road, Baiyun District, Baiyun, Gansu, China
E-mail: ksdjt@foxmail.com
Telephone: +86 156 9392 3686
Manufacturer:
Gansu Constar Technology Group Co., Ltd.
Address: No.10, Chuangxin South Road, Baiyun District, Baiyun, Gansu, China
E-mail: ksdjt@foxmail.com
Telephone: +86 156 9392 3686
EU responsible person:
BioDomi GmbH
Address: Schokoladenring 13, 65795 Hattersheim am Main, Germany
E-mail: arcontact@biodomieurope.de
Telephone: +49 178 5749814
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