Definition of spline in US English:



  • 1A rectangular key fitting into grooves in the hub and shaft of a wheel, especially one formed integrally with the shaft which allows movement of the wheel on the shaft.

    • ‘The male housing also includes splines which align with grooves on the female housing.’
    • ‘The splines slid smoothly into the oiled hub of the lock.’
    • ‘All along the east side of the floor is an external slatted screen of oak shutters supported on a semi-independent frame of oak members flitched to stainless-steel splines.’
    • ‘The cotter pin missed the male spline on the flap motor.’
    • ‘This means visually aligning the splines on the bottom bracket with the crank isn't an option - making installation testy.’
    • ‘Engineered to maintain original GM dimensions and process parameters, these axles are induction hardened and feature a 100-percent machined shaft and precision nobbed splines.’
    • ‘A chromoly rod pinch bolt on the non-driveside arm grips the 46 splines of the tubular axle.’
    • ‘Using the concave roller to carefully roll the spline into the groove over the screen.’
    • ‘A torsional load could be created if a force is applied at the tooth and an opposite force is applied at the splines.’
    • ‘UAW Local 2101 represents 17 workers at Wedin, where they manufacture ball screws, nuts, gears, shafts, splines and motion-control systems.’
    1. 1.1 A corresponding groove in a hub along which the key may slide.
      • ‘The hydraulic disc brakes are small and light, and the rotors fit onto splines on lightweight hubs.’
  • 2A slat.

    • ‘With those two sides nearly done, cut the next two corners and roll in the screen and the spline.’
    • ‘Cut a 7 ‘piece of spline and glue it into the grooved short end of the opening.’’
    • ‘Run a sharp utility knife or single-edge razor blade between the spline and the metal frame to cut off excess screening.’
    • ‘If you are using Fiberglas screening, simultaneously roll the screen and spline into the channel in this step.’
    • ‘A biscuit - a small wooden spline that looks like a flattened football - is glued and inserted into the slots as the boards are pressed together.’
    • ‘Tap splines until they are even with the outer edge of the molding.’
    • ‘To do this, use a small standard screwdriver or putty knife to lift one end of the spline from its track.’
    1. 2.1 A flexible wood or rubber strip used especially in drawing large curves.
      • ‘The great power of ISIS-Drive's open standard is also its weakness - the tapered spline requires great care to produce and the ISIS standard leaves manufacturing open to interpretation in some respects.’
      • ‘Therefore, there is more flexibility in the fitted splines than is strictly necessary to model the data.’
  • 3Mathematics
    A continuous curve constructed so as to pass through a given set of points and have a certain number of continuous derivatives.

    • ‘The 3D curves are incorporated into a wire part, and the curve elements are straight lines, arcs, circles, spline curves, spirals and curves on surfaces.’
    • ‘Did you know that the most pleasing shape to man is the spline curve?’
    • ‘Two generally accepted numerical approaches for obtaining this derivative are the spline fitting method and the incremental polynomial method.’
    • ‘The data was therefore fit nonparametrically to a smooth curve using the Dierckx algorithm for cubic spline curve fitting.’
    • ‘Garrett was quick to recommend the use of cubic splines for the representation of smooth curves.’


[with object]
  • 1Secure (a part) by means of a spline.

    • ‘The inner rotor portion of the pump is splined to one output on the axle and the outer drum portion of the pump is splined to the other.’
    1. 1.1usually as adjective splined Fit with a spline.
      ‘splined freewheels’
      • ‘In one of your past Q&A columns, you stated that you haven't heard of a Shimano splined crank breaking.’
      • ‘With Shimano, I have never heard of either the BB or the crank breaking since the advent of the splined bottom bracket.’
      • ‘The WCS is priced $50 below either of those rivals, but still uses Shimano's Octalink splined bottom bracket with hollow spindle.’
      • ‘That combination creates a lighter, stiffer crankset than older square-taper spindles and uses Shimano's widely available ES - 70 splined bottom bracket.’
      • ‘At the 105 level, Shimano employs many of its top-end Dura-Ace and Ultegra crank tricks, specifically Hollowtech hollow-forged aluminum arms and splined Octalink crank/bottom bracket interface.’
      • ‘The axle housing is a square carbon fiber tube containing individual elastomeric elements on a splined shaft.’
      • ‘I want to replace my BB / Crank with a splined version, but the spindle is offered in 113 mm.’
      • ‘Schwinn puts a lot of attention into a solid parts spec for the Moab - TruVativ's Firex ISIS splined crank is definitely built to take abuse.’
      • ‘The splined interface accepts the rotor much like freehub accepts the cassette - just slide the rotor on and cinch-down using a single lock-ring.’


Mid 18th century (originally East Anglian dialect): perhaps related to splinter.