Double Disc Cutter

Double Disc Cutter Specification

Double Disc Cutter	Diameter		Bearing Capacity [Tonne]	Cutter ring	Structure
product	[inch]	[mm]
	20"	508	35, 42	Optional	Assembly
	19"	483	35, 42	Optional	Assembly / Monoblock
	18"	457	28	Optional	Assembly / Monoblock
	17"	432	28	Optional	Assembly / Monoblock
	15 1/2"	394	25	Optional	Assembly / Monoblock
	14	356	20	Optional	Assembly / Monoblock
	12"	305	16	Optional	Assembly / Monoblock
	11"	280	13	Optional	Assembly / Monoblock
	10"	250	10	Optional	Assembly / Monoblock
	9"	220	9	Optional	Monoblock
	8"	200	8	Optional	Monoblock
	7"	180	8	Optional	Monoblock
	6 1/2"	165	5	Optional	Monoblock
	6"	150	4	Optional	Monoblock

Double Disc Cutter Structure

Double Disc Cutter vs. Single Disc Cutter: Selection Guide

In competent hard rock formations, single disc cutters are commonly preferred because they can withstand high individual cutter loads and support efficient rock fragmentation at high penetration rates. Twin disc cutters are often used in cutterhead center sections or in applications where cutter spacing is limited, providing additional cutting tracks within a compact installation space. They can help optimize cutterhead layout, improve cutting coverage, and enhance excavation efficiency under specific geological and machine design conditions.

Read more: Classification and Selection of TBM Cutter

Double Disc Cutter FAQs

• How do I select the right double disc cutter for my project?

Key factors include rock strength, TBM diameter, and abrasiveness. For rock strength ≥60 MPa, a single disc cutter is generally preferred. Double disc cutters work best in mixed ground or soft-hard transition zones.

Key selection factors include rock strength, abrasiveness, TBM diameter, cutterhead design, and available installation space. Single disc cutters are commonly used throughout the cutterhead, while twin or double disc cutters are often employed in center cutterhead zones where higher cutting density and optimized cutter arrangement are required.

• What are the typical wear limits for double disc cutters?

Replacement limits vary depending on cutter size, cutterhead design, and project specifications. In general, cutters should be replaced before excessive ring wear affects penetration performance or exposes critical cutter components.

See Replacement Standard of TBM Cutting Tools to learn more.

• How should double disc cutters be inspected and maintained?

Daily inspection should check cutter ring wear, mounting bolt tightness, and seal condition. Regular maintenance includes cleaning, measuring, and timely replacement of worn parts during cutter replacement operations. See TBM Disc Cutter Inspection and management to learn more.

• What are the most common failure modes for double disc cutters?

Failures fall into normal wear (progressive ring reduction) and abnormal damage such as eccentric wear, cutter ring cracking, bearing failure, or seal leakage. Abnormal damage is often avoidable with proper tunneling parameters and daily checks. See Analysis of TBM Disc Cutter Damage And Countermeasures to learn more.

• What causes sealing failure in double disc cutters?

Sealing failure is often caused by high-temperature operation, abrasive particles entering the seal cavity, or normal seal aging. Once seals fail, lubricant leaks out and rock cuttings invade the bearing, leading to bearing damage and cutter failure. See Analysis of TBM Disc Cutter Damage And Countermeasures to learn more.

• How can I tell if a double disc cutter needs emergency replacement?

Signs include a sudden drop in penetration rate, abnormal noise or vibration from the cutterhead, visible cutter ring cracking, severe spalling, excessive wear, or missing carbide inserts (where applicable).  See Replacement Standard of TBM Cutting Tools to learn more.