INDEX TNL18

$200,000 - $350,000 Updated 2026-03-16

Key Specifications

max bar diameter

18 mm (0.71 in)

guide bushing

Yes (standard), guidebushless option available

main spindle speed

10,000 RPM

counter spindle speed

10,000 RPM

live tooling positions

Multiple (main and counter spindle)

live tool speed

8,000 RPM

Overview

The INDEX TNL18 is a compact CNC sliding-headstock (Swiss-type) lathe from INDEX-Traub, built for high-precision machining of small-diameter complex parts from bar stock up to 18 mm (0.71 in) in diameter. Swiss-type machining at this diameter is the domain of precision medical components, watchmaking elements, electronic hardware, and miniature fluid power fittings — small, complex, close-tolerance parts where complete machining from bar stock in one pass is the only economically viable approach.

The TNL18 uses INDEX's proven CNC platform with Siemens SINUMERIK control, providing full programmability for the complex turning, milling, drilling, and threading operations that define Swiss-type part production. The sliding headstock advances the bar through a guide bushing positioned close to the cutting zone, virtually eliminating workpiece deflection on long, slender parts — the fundamental advantage of Swiss-type over fixed-headstock machines for long/slender work.

Live tooling is standard at multiple positions, enabling cross-drilling, milling, polygon turning, and thread whirling without secondary operations. A counter-spindle enables back-working on the part's second face, completing front-and-back machining in a single bar-feed cycle. The machine's small footprint — Swiss-type lathes are notably compact — allows efficient use of floor space in precision manufacturing cells.

At $200,000-$350,000 new, the TNL18 is priced above Citizen and Star Swiss-types in the 18mm class, reflecting INDEX's German engineering premium. Direct competitors include the Citizen L20, Star SR-20, and Tsugami S206. INDEX machines command a premium based on build quality and the German industrial manufacturing pedigree that some automotive and aerospace customers specifically require from their machine tool suppliers.

Full Specifications

Parameter	Value
Max Bar Diameter	18 mm (0.71 in)
Guide Bushing	Yes (standard), guidebushless option available
Main Spindle Speed	10,000 RPM
Counter Spindle Speed	10,000 RPM
Live Tooling Positions	Multiple (main and counter spindle)
Live Tool Speed	8,000 RPM
Max Part Length	200 mm (7.9 in)
CNC Control	Siemens SINUMERIK 840D sl
Bar Feed Interface	Compatible with standard bar feeders
Machine Footprint	~2,000 x 1,800 mm
Guest Name	Dietary Restriction
David	None
Bob	None
Nancy	None
Mary	Vegetarian
Formula	Formula Output
Index	3
Goal	Formula
Find Marys Dietary Restriction	=INDEX(A1:D6, MATCH("Mary", A1:A6, 0), MATCH("Dietary Restriction", A1:D1, 0))
Find Who Is At Table Number 2	=INDEX(A1:D6, MATCH(2, D1:D6, 0), MATCH("Guest Name", A1:D1, 0))

Specifications sourced from index-group.com — verified 2026-03-28

Strengths & Limitations

Strengths

Guide bushing support eliminates workpiece deflection on long/slender parts — the core advantage of Swiss-type machining
Siemens SINUMERIK 840D sl control is the industry standard for precision European machine tools — excellent CAM support
Counter-spindle enables complete front-and-back machining in a single automated cycle from bar stock
Live tooling at multiple positions eliminates secondary operations for cross-drilling, milling, and threading
INDEX German build quality and precision machining heritage in a compact Swiss-type format
Guidebushless option available for shorter parts that do not require guide bushing support

Limitations

18 mm bar diameter limits the machine to very small parts — the TNL32 is required for 20-32mm diameter work
INDEX Swiss-type pricing ($200K-$350K) is significantly above Citizen L20 and Star SR-20 at similar 18-20mm capacity
INDEX's Swiss-type dealer and applications support network in North America is smaller than Citizen or Star
Siemens 840D sl is a premium control but less common in Swiss-type shops than Fanuc 32i used by Citizen and Star
Small guide bushing diameter limits the material that can be bar-fed without additional preparation

Best For

Medical device manufacturers producing bone screws, cannulated screws, and small implant components in titanium and stainless Defense and aerospace suppliers machining miniature precision fittings, actuator components, and small housings Electronic hardware manufacturers producing small turned components in brass, copper, and stainless Shops with European OEM requirements that specifically require German machine tool pedigree in their supply chain qualification Precision watchmaking and instrument manufacturers machining small complex components with Swiss-level accuracy

Frequently Asked Questions

01 How does the INDEX TNL18 compare to the Citizen L20?

Both are Swiss-type lathes in the 18-20mm diameter class. The Citizen L20 is priced significantly lower and has excellent North American dealer support. The INDEX TNL18 offers German engineering and Siemens 840D sl control that some customers specifically require. For most applications, the Citizen L20 provides equivalent capability at lower cost. Choose the INDEX when German machine origin is a customer requirement.

02 What is the guide bushing option on the TNL18?

The guide bushing is a precision collet-style support positioned very close to the cutting zone. It prevents deflection of the bar stock during machining, which is critical for long, slender parts with length-to-diameter ratios above 3:1. A guidebushless option is available for shorter parts that do not require the guide bushing support — this eliminates the need for precision ground bar stock required by the guide bushing.

03 What materials can the TNL18 machine?

The TNL18 machines all standard CNC turning materials within its 18mm diameter capacity: steel, 304 and 316 stainless, titanium alloys (Ti-6Al-4V), aluminum, brass, copper, and engineering plastics. For medical applications in titanium and cobalt-chrome, the machine's live tooling and counter-spindle enable complete part production in the required materials.

04 Can the TNL18 do thread whirling?

Yes, thread whirling is a standard capability of Swiss-type lathes including the TNL18. Thread whirling uses a ring-style cutting tool that produces external threads in a single pass at high efficiency — particularly useful for bone screw threads in orthopedic implants. The process produces threads significantly faster than single-point threading and is standard in medical device manufacturing on Swiss-types.