Product Description
CMT 316.080.12 Countersink for 4 Flute Drills - 5/16" (18mm) Left-Hand Rotation is a precision-ground carbide countersink designed for use with 4-flute dowel drills on multi-spindle and CNC boring equipment. Featuring a 45 deg. cutting angle and left-hand (LH) rotation, this tool delivers clean, accurate countersink profiles in a single pass through panel materials and solid wood. The 18mm cutting diameter and 8mm bore diameter make it a purpose-built fit for high-feed-rate boring operations where consistent results and extended tool life are priorities.
Key Features
- 45 deg. Cutting Angle - produces a precise, industry-standard countersink geometry that ensures flush or recessed fastener seating without secondary operations.
- Left-Hand (LH) Rotation - engineered specifically for left-hand spindle configurations found on multi-spindle CNC boring machines and panel processing centers, eliminating the need for adapters or workarounds.
- 18mm Cutting Diameter with 8mm Bore - sized to pair directly with 4-flute dowel drill shanks, allowing fast, repeatable changeovers and secure tool holding on compatible boring heads.
- Hardmetal (HW) Carbide Construction - tungsten carbide material delivers superior hardness and wear resistance, extending tool life when machining abrasive panel products such as chipboard, MDF, and laminated boards.
- 2-Tooth Cutting Configuration - dual cutting edges provide balanced cutting forces and smooth surface finishes on the countersink face, reducing tearout in coated and laminated panels.
- Compact 15mm Total Length - the short profile minimizes tool overhang and vibration, contributing to tighter dimensional tolerances and cleaner hole geometry at production feed rates.
Why This Product
- Designed for left-hand spindle boring setups, this countersink integrates directly with 4-flute drill configurations - eliminating compatibility issues and keeping production lines running without custom tooling.
- Hardmetal (HW) carbide construction stands up to the abrasive demands of chipboard, MDF, HDF, and laminated panels, meaning fewer tool changes and lower cost per hole over time.
- The 45 deg. angle and 2-tooth geometry work together to produce clean, burr-free countersink profiles in both solid wood and coated panel materials - reducing the need for manual cleanup or rework.
- At just 15mm total length, this compact countersink is built for tight multi-spindle boring head arrangements where space between adjacent tools is limited, making it a practical choice for high-density CNC boring centers.
Specifications
- Manufacturer Part Number: 316.080.12
- Brand: CMT Orange Tools
- Cutting Diameter: 18mm
- Bore Diameter: 8mm
- Total Length: 15mm
- Cutting Angle: 45 deg.
- Number of Teeth: 2
- Rotation: Left-Hand (LH)
- Blade Material: HW (Hardmetal Carbide)
Approved Applications
- Multi-Spindle CNC Boring Machines
- CNC Boring Centers
- Panel Processing Centers
- Boring Machines with Adapter or Chuck
- Chipboard and Particleboard
- MDF and HDF
- Hardwood and Softwood
- Plywood
- Laminates and Coated Panels
Frequently Asked Questions
What rotation direction does this countersink use, and why does it matter?
This countersink uses left-hand (LH) rotation. Multi-spindle CNC boring machines and panel processing centers frequently include spindles that rotate in the left-hand direction, and using a right-hand tool on a left-hand spindle would cause the tool to unscrew or fail to cut properly. This LH-specific countersink is engineered to work correctly and safely on those spindle positions.
What is the cutting diameter and bore diameter of this countersink?
The cutting diameter is 18mm and the bore diameter is 8mm. The 8mm bore allows the countersink to be mounted directly onto compatible 4-flute drill shanks or boring head adapters with an 8mm arbor.
What material is the cutting edge made from?
The cutting edges are made from HW hardmetal carbide. Carbide is significantly harder than high-speed steel, which translates to longer tool life and consistent cutting performance when working with abrasive engineered wood products such as chipboard, MDF, HDF, and laminated panels.
What cutting angle does this countersink produce?
This countersink is ground to a 45 deg. included cutting angle. This geometry is commonly used in furniture and cabinet panel drilling operations to create a countersink profile that accommodates standard hardware and fasteners at the correct angle without additional finishing steps.
Reviews
FAQs
Standard Shipping is free on most orders over $50 within the contiguous US. If the order is under $50.00, the shipping is $9.99 set fee for shipping within the contiguous US.
Most of our products will ship within 1 to 3 Business Days. Some Special order products will ship within 2 to 5 Business Days. Preorders will be shipped to you on a first come first serve basis as soon as available from the manufacturer. Items that are "Made-to-Order" (Custom order products) will be shipped when fabrication is completed, shipping and delivery times will vary and depend on manufacturing.
Products that are shipped directly from the manufacturer will have processing and fulfilment times subject to manufacturer availability.
Preorders are shipped on a first come first serve basis as soon as available from the manufacturer, the sooner you place your Preorder the sooner your order will ship.
Freight shipping Policy:
Orders/Items too large or heavy may require special handling/Shipping and may require to be sent by truck. Someone must be present to accept truck deliveries. Standard truck delivery is to a dock facility designed to receive freight. You will be notified within 24 hours of ordering to confirm delivery. Lift gates for deliveries are available for an additional fee.
We offer Financing options through Clicklease
Please email your Return request to info@FactoryDirectSupplyOnline.com
Include the order number and the reason for your return.
All returns, regardless of their categorization, must include all original parts, be in their original packaging, and in the condition in which they were received. You may not qualify to receive a refund If the returned item is used, damaged, missing any parts, or is damaged during return shipping.
Checkout our complete Return policy
You can contact us through our contact page! We will be happy to assist you.