Questions & Answers

Ropes and accessories

  1. What difference is there between Mastrant Classic ropes (P, Q, S, C, R) and Mastrant-M? The difference stands in parameters. Ropes from Classic product line are the basic ropes optimized for good price to performance ratio, whereas type M have approximately doubled strength and simultaneously half the stretch compared to type Classic. They are also lighter because the rope core is made from high strength Dyneema® fibres.
  2. When is it better to use Premium rope (M) instead of Classic? When one needs the lowest weight and wind resistance (long ropes holding wire antennas, or supporting large beam elements, or expeditions where low weight is crucial). Also when the anchor points on the ground need to be placed close to the tower (less than 50% of the anchor height – depending of type of tower – the higher stress needs to be calculated individually) and finally, for any big towers with big antennas.
  3. When I am looking at Dyneema ropes for maritime use, the strength eg. with 10 mm Dyneema is well over 10.000 kg, but your Mastrant M rope with similar diameter has "only" 3850 kg strength, even the core material is the same. Can you explain why? Our declared breaking strength of ropes is strength really measured – each production series. It must be always 3% or more higher than in our specification. There on the market is also another approach – the theoretical BS calculated based on specification of Dyneema fiber and number of fibers (diameter). This theoretical strength is always much higher.
  4. What difference is there between Mastrant ropes and Kevlar ropes? Kevlar, like Dyneema®, uses high strength fibres. While Kevlar is made from aramid the Dyneema® is made from special sort of PET. Kevlar is not UV resistant and its fibres tend to break when bending over a small radius.
  5. What about comparing Mastrant ropes with Phillystran? Mastrant-P has about 80% of strength of Phillystran of the same diameter. Mastrant-M has about 30-65% higher strength than Phillystran – but the bigger the diameter the smaller difference. Nevertheless, any Mastrant solution of any strength is many times cheaper.
  6. What makes Mastrant-M better rope for tower guys than pure Dyneema rope made for maritime use? This question needs more answers:
    1. There are several types of Dyneema. Also, there are other producers (and brands) of HMPE ropes (the chemical principle of Dyneema). In Mastrant-M we use special version of HMPE fibers – Dyneema DM20. The biggest advantage is that it does not creep. Even though this material is much more expensive that older types of Dyneema or other HMPE fibers, the stability is very important for guying so in 2013 we switched to DM20 and Mastrant-M was born.
    2. For guying there are usually important also mechanical features. Using two (or three in diameters 6 mm and up) layers of materials in the rope significantly increase mechanical durability. Also, pure HMPE rope is “slippery” (on touch).
    3. If you are considering pure standard HMPE rope (Dyneema SK75, SK79, SK99, Nexsteel, ...), consider also our HMPE ropes D-F3. With these ropes you would need from time to time re-tighten the tensioners.
  7. I want to replace steel ropes by synthetic ones – which ropes should I use for replacement? Refer to Steel rope replacement.
  8. I have a Rohn® tower and I want to use Mastrant ropes to guy it – which ropes should I use? Refer to: Guying ROHN Towers with MASTRANT Ropes.
  9. What is the expected lifetime of Mastrant ropes? Like steel ropes producers we recommend replacing them after 5 years of use. However, we have experience with flawless 13-year-old installations.
  10. Do I need to buy a complete reel? How long is the rope on the reel? Standard is 100m or 200m of rope on the reel. Some diameters are 31m on the reel. However, we can deliver any length you want (ropes longer than 200m are available on special order). The ropes of standard length are cheaper. Aside from standard ropes we offer also “ready-made” ropes with thimble compressed-in on one end.
  11. What a rope and how long do I need for ...? We offer free calculation service of ropes strength and length needed for your project. Apart from that we have on-line calculators on our web pages which you can use for calculation yourself. These tools are also available in form of Android application – look for “Mastrant” on Google Play store. For basic orientation we have prepared typical installations and recommended ropes: Typical installations
  12. What elongation (stretch) percentage means? The elongation in our data sheets is relative change of the length measured between “pre-tension” (10% of breaking strength) and “working tension” (30% of breaking strength).
  13. Why don't you supply clamps with safety locking nuts? We fully understand your concerns. In reality, if the clips are used properly – and that means properly tightened, it is not possible for the nuts to spontaneously loosen. The reason is that there is always strong counter-pressure caused by elasticity of ropes. The fact is that the clips were designed by much smarter people than me without washers or locking nuts - and this applies to all types of rope grips. Also, we have never received any feedback that nuts were loosening when installed on the rope, on the other hand, losing nuts during transportation in a pack or pocket is quite common. My personal experience (OL5Y) proves that they will not loosen on the rope, if properly tightened.

Personal safety

  1. What difference is there between particular harnesses? The BASIC harness is a basic safety harness. Comparing to other types it doesn’t contain the adjustable waist belt. The difference between LX2 to LX5 is in flexibility, sling width, the way of fixing (LX4 and LX5 use quick acting buckles) and comfort (LX3 and LX5 are designed for long periods of use).


  • Mastrant-Q 2. 2. 2020

    In 2019 we have developed replacement for “thick” ropes Mastrant-P. The line of diameters 6-8-10-12-14 will be replaced by new ropes Mastrant-Q with complex cores (Polyester and Polypropylene fibers) in diameters 6-8-11-14. These new ropes belongs to CLASSIC class and are even less expensive than Mastrant-P. Details.

  • Light version of Mast clamps available 27. 2. 2019

    Our original stainless steel mast clamps are already available also in light version. Guying Mast Clamp MA2 Light, Stainless

  • Hamfests in 2018 3. 12. 2018

    In November we were on the last show in this year. Our team visited 21 shows in USA, England, Germany, Italy, Spain, Switzerland, Belgium, Portugal and in the Czech Republic. It is the most hamfests in the history that Mastrant has attended. We were very pleased to meet you and hope to see you again in the future!

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