Thomastik-Infeld JF345 Jazz Nickel Flatwound 5-String Bass Strings

The Thomastik-Infeld JF345 is widely considered the "holy grail" of flatwound bass strings. Unlike traditional stiff flatwounds, the Jazz series is engineered with a highly flexible round steel core, providing a feel and response that is remarkably supple and expressive. These strings are specifically designed for 5-string bassists who demand a sophisticated, deep, and balanced tone that sits perfectly in any mix, from jazz and fusion to R&B and rock.

The Flatwound Standard for 5-String Players

What sets the JF345 set apart is the legendary 136-gauge low B string. This string is meticulously balanced to provide a clear, focused fundamental without the "muddiness" often found in other sets. The outer winding is a true ribbon flatwound made of a special nickel alloy, polished to a mirror-smooth finish. This ensures zero finger noise and a buttery-smooth feel that is as easy on your frets as it is on your fingers.

Silk Inlay Technology

Between the steel core and the nickel ribbon winding, Thomastik-Infeld utilizes a genuine silk inlay. This provides additional flexibility and helps dampen harsh overtones, resulting in the iconic "thump" and warmth associated with classic recordings.

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Key Performance Features

  • True Ribbon Flatwound: Polished nickel alloy winding for a smooth feel and reduced fret wear.
  • Round Steel Core: Enhances flexibility and vibration, avoiding the "bridge cable" feel of other flats.
  • Long Scale (34"): Designed to fit standard long-scale 5-string basses with perfect tension.
  • Unique Sonic Profile: Delivers a deep, organic sound with a complex midrange that cuts through the mix.
  • Legendary Low B: A specialized .136 gauge ensures the lowest string remains articulate and punchy.

Detailed Specifications

Instrument Type 5-String Electric Bass
Scale Length Long Scale (34")
Winding Type True Ribbon Flatwound
Material Nickel Alloy w/ Silk Inlay
Gauges .043, .056, .070, .100, .136
Product Code JF345

Frequently Asked Questions

How long do these strings last?
Because they are flatwound and resistant to dirt buildup between windings, Thomastik Jazz Flats are famous for lasting years. Many players find that the tone actually improves as the strings "age" and settle in.

Are these too "floppy" for high-speed playing?
While they are more flexible than standard flats, they maintain excellent tension. They are designed for a nuanced touch, allowing for incredible dynamic control and effortless vibrato.

Will these fit a 35" scale bass?
The JF345 is optimized for 34" scale instruments. For 35" (extra-long) scale basses, we recommend checking the "long scale" compatibility carefully to ensure the silk-wrapped portion does not cross the nut.

SKU JF345
Barcode # 9003918701596
Brand Thomastik-Infeld
Shipping Weight 0.2000kg
Shipping Width 0.180m
Shipping Height 0.030m
Shipping Length 0.190m
Shipping Cubic 0.001026000m3
Unit Of Measure ea

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