Series 29 Utility Single Block with Becket and Rivet Eye


In stock online.
Model # 538744 | Mfg # RF188 | UPC # 9316800079575

Light-weight economical blocks for control lines.

Not all control line blocks on a boat require two-stage bearings that evolve from years of R&D—and the expense that goes with them. Sometimes the system just needs a simple, but solid block. Utility blocks are just the answer for these situations, but Ronstan takes simple a step further by using top quality materials. Commonly used for dinghy applications, these blocks feature 316 stainless steel cheeks for strength and superior corrosion resistance. UV stable acetal sheaves provide durability for a long service life. Each block is riveted together and requires virtually no maintenance—just a little rinse now and again. The rivets are hollow and can be used to fasten the blocks with screws, shackles or lashed. For extra purchase the rivet can be used as a becket. There is a utility block for almost any light to moderate load application. Explore the possibilities with confidence using Ronstan utility blocks.

This 29mm single block with rivet eye and becket is a workhorse. Suitable for smaller control lines and systems, the rivet eye works best with a shackle (sold separately). Great for use in backstay systems, Cunninghams, internal outhauls and more.

Key Features

  • Solid simple standard bearing block
  • 316 stainless steel cheeks for strength and superior corrosion resistance
  • Acetal sheaves offer UV resistance
  • Maintenance-free
  • Riveted together
  • Can be mounted using fasteners, shackles or lashed
  • Ideal for:
    • Boom vangs
    • Halyard tuning systems on dinghies
    • Outhauls
    • Cunninghams
    • General control line use

Ronstan Utility Block Selection Guide

Sheave DiameterLine Compatibility
19mm3/16" (5mm)
25mm3/8" (10mm)
29mm5/16" (8mm)


Series 29 Utility Single Block with Becket and Rivet Eye

Name Value
Ball Bearings Plain Bearings
Becket Becket
Diameter 5/16 Inch or 8 mm
Direction Any
Integral Cleat No Integral Cleat
Mount Type Fixed Lashing Eye
Ratchet Non Ratcheting
Safe Working Load 660 Pounds
Sheave Diameter 29 mm
Type Single
Weight 1.2 Ounces


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