About BoltShield®

Bolt Thread and nut protection BoltShield® TD and TR types
Bolt Thread and nut protection BoltShield® TD and TR types
Bolt and nut protection BoltShield® TD type
Bolt BoltShield® TD type Screw-on System
Bolt and nut protection BoltShield® TD type
Bolt and nut protection BoltShield® TD type
Bolt and nut protection BoltShield® TD type
Bolt and nut protection BoltShield® TD type
Bolt thread protection BoltShield® TR type
Thread protection BoltShield® TD and TR Types
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BoltShield® are screw-on metal caps designed to protect stud bolts and nuts from thread damage, dirt and considerably help to prevent corrosion.

BoltShield® metal protection caps are the best bolt thread protection (BoltShield® TR Type) and bolt & nut protection (BoltShield® TD Type) for all industrial applications.

By using BoltShield® caps you will extend the life of bolts and nuts and make maintenance and repair procedures easier and faster.

They will help to reduce expensive plant downtimes, thus saving money and time.
BoltShield® metal protection caps are widely used in refineries,petrochemical plants, LNG plants, offshore platforms, steel structures. They are commonly installed on heat exchangers, reactors and process equipment operating at temperatures up to 550°C and over, where common plastic caps would melt.
You can find BoltShield® caps to protect bolts on valves, pipelines, traffic sign posts, bridges, wind turbines and several other applications where bolts and nuts need to be protected.

Both types of BoltShield® caps are available in stainless steel (304/316), aluminium, carbon steel, zinc electroplated carbon steel and can be supplied for bolt sizes ranging from ½” to 6”M12 to M100 (UN/metric ISO threads).

To meet all customers' needs BoltShield® caps are also available in custom-made sizes and coated upon request!

BoltShield® caps have a special internal thread, named Screw-On System, that ensures a strong and secure fixing to the bolt by matching the bolt thread (have a look at How it Works).
BoltShield® Caps are bolt protections designed to be installed manually. No extra tools are required, and they can be easily installed and removed when needed.

Available Materials

  • Aluminium


    Light but strong, and anti-static. Aluminium is among the most widely used materials where ASTM A193 B7 stud bolts and A194 2H hex nuts on pressure vessels, reactors, heat exchangers, columns and other process equipment in the oil & gas and petrochemical industries have to be protected. Aluminium bolt caps are also a good solution for the protection of ASTM A320 L7 bolts in low temperature service applications, as well as for ASTM A307 carbon steel bolts. Last but not least, aluminium bolt protection caps have a beautiful appearance, shiny and aesthetic. Available sizes: ½” to 4” – M12 to M100 (UN/metric ISO threads).

  • Stainless Steel

    Stainless Steel

    (AISI 304 / AISI 316) – Our top-line BoltShield® caps.  Stainless steel protection caps are in high use in offshore applications, plants located near the coastline or high corrosive environments. Stainless steel caps are perfect to protect B8 and B8M stud bolts and nuts. Can you think of a better protection for your stainless steel bolts than stainless steel protective caps? Available sizes: ½” to 2”1/2 – M12 to M64 (UN/metric ISO threads).

  • Carbon Steel

    Carbon Steel

    Carbon steel caps are the best solution for coated bolts and nuts, as they are suitable for different types of coating (zinc, cadmium, paint etc.), therefore maintaining the correspondence between bolt and nut and the protection cap. We can offer zinc coated or paint coated carbon steel protective caps for bolts upon request. Available sizes: ½” to 4”M16 to M100 (UN/metric ISO threads).

  • Zinc Electroplated Carbon Steel

    Zinc Electroplated Carbon Steel

    This is an excellent coated solution that we offer at the same price of raw carbon steel caps! Here zinc is applied to the raw material (sheet metal carbon steel) through electrolysis, thus creating a layer that protect the metal base against corrosion. BoltShield® made of zinc electroplated carbon steel are the ideal choice if you need to protect galvanized bolts and nuts, or when you want to provide extra protection from corrosion to B7 or L7 studs. As an alternative, we offer hot-dip galvanizing at a little extra cost. Available sizes: ½” to 4” M12 to M100 (UN/metric ISO threads).

BoltShield® Benefits & Features

There are several reasons for using BoltShield® caps.
Here below just some of the benefits that you can get from BoltShield® metal caps:

  • Thread protection (protect bolt threads from accidental damage that may occur during handling, transportation and maintenance)
  • Corrosion prevention (ASTM B-117 tested)
  • Make maintenance and repair procedures easier and faster
  • Avoid time-consuming destructive bolt removal procedures
  • Help to reduce plant downtimes, thus save money & time
  • They are designed to withstand high temperatures (up to 550°C: where common plastic caps would melt)
  • The Screw-on System allows to easily install and remove caps when needed
  • These caps are available in standard sizes from ½” up to 6" diameter (other sizes and coatings upon request)

Why BoltShield® is Cost-Effective

BoltShield® caps are cost-effective not only because they help reducing the time, thus the cost, of maintenance operations and plant downtimes, but also because their use will prominently extend the life of your bolts and nuts.

These kind of bolt thread protections are reusable and once tightly fixed onto bolts they will last for years.

There are other ways to prevent corrosion, such as coatings or stainless steel. However coatings are expensive and may not be enough, as during transportation, handling and assembling they may wear out. Re-coating is expensive and time-wasting. This will result in unprotected bolts and nuts, which would soon be affected by corrosion. Stainless steel is clearly a good solution for corrosion prevention, but it is also really expensive. Finally, neither coatings nor stainless steel can prevent bolt threads from accidental damage that could compromise the integrity of your bolts.

On the contrary, BoltShield® caps provide corrosion prevention along with thread protection, and all at a cheaper price.