Tent Pole Materials
Tent poles for family tents come in a variety of materials- most commonly steel, fiberglass and aluminum. Steel poles are sturdy, but heavy, which means they are only really suitable for car camping. They also lack flexibility, so should a storm break and your tent gets blown down, the chances are you’ll be left with some bent poles. Fiberglass, on the other hand, is light and often used instead of, or in combination with, steel poles. Fiberglass tent poles are cheap to produce, and consequently they are favored by many tent manufacturers, and although there are a substantial number of tent manufacturers who still use fiberglass, nowadays most top quality tents come with aluminum poles. Unlike fiberglass, which has a tendency to splinter with repeated use, aluminum, with its higher strength-to-weight ratio and greater durability, makes the perfect choice for backpacking and car-camping tents.
Aluminum Tent Poles
You may notice when you check out tent specifications that aluminum poles are often listed with numbers after them. Most of us probably don’t know whether they’re important or not, but serious backpackers often want to know exactly what grade of aluminum their poles are made from because that indicates how robust the poles are likely to be.
So, what do all the numbers mean?
Aluminum alloys, in which aluminum is the principal metal, come in grades, from 1000 series through 9000 series. You will find many tent manufacturers use tent poles made from 6000 or 7000 series aluminum alloys.
6000seriesalloys are a blend of aluminum, magnesium, silicon and other trace elements. The alloy 6061 is widely utilized in yacht, aircraft and bicycle manufacturing, but it is also commonly used for tent poles, e.g.,Mountain Hardwear Corners tents. This alloy is strong and resistant to corrosion, even if scratched.
7000 seriesaluminum alloys are a blend of aluminum, zinc and other trace elements. This combination gives the highest strength of any aluminum alloy. 7001 has the highest yield strength (the point at which a pole becomes permanently bent) of the 7000 series alloys (7001, 7178, 7075). For this reason, 7001 aluminum is frequently used in tent poles, and it has the added benefit of having good corrosion resistance.
You may also see aluminum poles listed with not only a number, such as 7001, but also a T6. This stands for the temper process. T6 is used because it produces a less brittle, high yield strength pole.
The most popular brand of aluminum poles are produced by Dongah Aluminum Corporation (DAC) of Korea. Their first Featherlite™ pole was created in 1997, using aluminum alloy 7001 with T6 temper. Up until then it was practically impossible to reduce pole weight, yet maintain its strength and flexibility. So, how did they achieve this?
Featherlite™ poles eliminate the ferrule, the weakest part in conventional poles, and reduce the joint weight. They use Seamless Extrusion, an expensive and slow process that ensures the microstructure of the aluminum is uniform. With no welding and less internal stress, these poles are highly resistant to Stress Corosion Cracking (SCC), a common problem in high-strength aluminum.
So, by removing weight from the joint, which usually accounts for 20% of the total weight of the pole, DAC were able to reduce the overall pole set weight by approximately 15%, a real bonus for back-packing campers.
Pressfit™ technology. Until DAC introduced this revolutionary jointing technology, tent pole inserts were fixed by gluing or crimping them in place. Both of these techniques can lead to stress fractures in poles. However, Pressfit™ expands the end of the insert tube so that it remains tightly gripped by the main tube, creating a durable, heavy-duty joint.The North Face Mountain Manor and Meadowland, and Marmot Halo and Limestone tents all use Pressfit pole technology.
By combining Featherlite™ and Pressfit™ technology, DAC have produced a thin walled, yet extremely strong tent pole. The Featherlite NSL™ (new sleeve) has been one of DAC’s most successful innovations and is now widely used by tent manufacturers, e.g.Sierra Designs Lightning HT 4 and Big Agnes Copper Spur.
DA17™ aluminum poles are made from a new alloy, researched and developed specially to enable them to produce larger diameter poles of reasonable quality, yet lower costs than Featherlite™ or Featherlite NSL™.Using much of the same innovative technology, DA17™ poles are used to build good quality family camping tents, e.g.Kelty Trail Ridge, and Sierra Designs Meteor Light and Wu Hu Annex.
TH72M™, the latest of DAC’s lightweight aluminum innovations, has enabled them to produce aluminum tubing that is stronger and lighter than ever before. The TH72M™ technology minimizes Stress Corrosion Cracking, allowing production of thinner walls with no reduction in strength.
Green Anodizing™ was developed by DAC to minimize the toxic chemicals used in the anodizing process. Aluminum is anodized to make it more resistant to corrosion and this process used to require nitric and phosphoric acid in the polishing stage. However, after almost ten years of research, DAC have achieved their goal of eliminating this stage of the process with their innovative Green Anodizing™ technology.