The best piece of advice you can be given regarding tent pegs and which ones to use, is to have a variety of pegs in your tent setup. A mixture of pegs will be the best approach to camping as the soil conditions can vary, so having a range of pegs to choose from will cover most scenarios.
Different pegs will outperform others under certain conditions, you may encounter different conditions within the same trip. So taking different types of peg on your trip can make tent setup easier over a wider range of environments.
Best practice is to take enough pegs for each pegging point on the tent, then enough for each storm guyline attachment, as having the ability to utilise all of these in adverse weather conditions is vital. Then taking the total of the above and adding two spare pegs is always a good idea just in case.
Taking pegs of different lengths is advised as different points of the tent will require a longer or shorter peg to be the most effective. Peg points that are attached to the inner will be better with shorter pegs as the inner is not subjected to higher levels of tension, unlike guylines and storm guy points on the outer of the tent. Shorter pegs could be used for peg points inside the vestibule in adverse ground conditions where a longer peg would get in the way.
Pegs need to be strong and durable so there are a number of materials that they are commonly made from.
Titanium - Titainuim generally has the greatest strength to weight ratio for outdoors equipment. It is less likely to bend compared to steel or aluminium, it weighs considerably less but is also much more expensive.
Plastic - There aren't many brands who use plastic for pegs but there are still some excellent designs out there. Plastic is cheap, easy to clean and performs well in softer ground. However, it does break and deform easily in stony ground or if you place pressure on it incorrectly.
Steel - Steel is commonly found in cheaper tent sets due to it's cost effective, classic designs. Steel pegs are strong and durable. They are best used in stony ground. The steel can rust over time and they are much heavier than the other materials mentioned here.
Aluminium - Lightweight but can deform easily
Aluminium pegs are generally graded from a 1000-8000 series. 7000 Series is the most common rating for tent pegs as this is a Zinc Alloy with a low ratio of magnesium, which is one of the strongest alloys available, making it stronger than most types of steel. The 7000 series aluminium is commonly used in aerospace industries due to the excellent strength-to-weight ratios, they are extremely hard, strong and stress resistant.
The ground type of your pitch area will greatly affect the effectiveness of your tent pegs and should therefore, influence the types of tent pegs you decide to take with you. Obviously it's not always possible to know this ahead of time but knowing the general area you are aiming to camp in, such as valley floors or exposed mountain tops will give you a good start.
Some key points:
The lightest variation of these pegs is the pin peg, which comes in around 1-2g per peg. These are suitable for pegging out groundsheets but when used in softer ground conditions they don't provide a lot of holding power for guylins. The thinner versions of wire pegs can hold well in harder ground but when under tension they tend to rip through softer ground. They are incredibly small by nature and are generally painted with a bright colour to help you find them in the ground.
Other names for Wire Pegs include: Shepard's Hook/Roundwire Peg/Pin Peg/Tooth Peg
V Pegs are one of the most common types of pegs provided by manufacturers with tents. This is because they provide a good hold in a wide range of soil types. The longer the peg the stronger the hold in soft ground types such as sandy soil. The V pegs are usually made from aluminium or titanium. Those made from titanium are some of the lightest yet strongest holding pegs on the market.
The Y shaped tent peg is often provided with stronger or heaviers all season tents. This is because they are stronger than the V shaped tent peg, providing a multi-directional hold. A staple with all higher specced backpacking tents, usually made from either aluminium or titanium to keep the weight down, they are good all round pegs for smaller tents. The point of weakness in the design is the narrow top part which can snap if under a lot of pressure.
Other names for Y Pegs include: Tri-Beam
Nail pegs are designed to be nail-like, with a long, thin profile. The thin shaft of these pegs makes it easier to push them through stones found under the soil and the design is meant to avoid bending the pegs, but this can still happen if you hammer the peg directly into a rock under the ground. Ideally suited to hard, rocky ground they do not deliver a good hold in softer ground.
Twister pegs have a large surface area due to the design which essentially twists a Y peg in order to maximise the amount of grip the peg can provide in softer soils. The larger surface area of these pegs also provides strong, secure points for large tarps and shelters in windy conditions. The wider the peg the bigger the twists which, directly translates to more hold in softer ground, sand and hard snow.
They are usually designed with longer, wider and concave shapes to provide a greater surface area that enables a firm hold in sand or snow. The holes found in the pegs let snow freeze through them providing extra stability and provide options for tying on multiple guylines to one peg. Sand and snow pegs can perform best when used in a 'deadman's anchor' configuration where the peg itself is buried at a perpendicular angle to the direction the guyline will be pulled from, providing maximum holding power.
Plastic pegs usually provide a large surface area for a low weight. They are best used in soft ground where they provide great levels of grip, especially for guylines. With a range of benefits including them being long lasting, durable, rust free and lightweight, they are a very promising peg type that are surprisingly rare. Not so good in harder ground as they can bend easily and will if they are pushed into ground where stones are present. They are often brightly coloured so they can be found easily.
Plastic pegs with a larger surface area and serrated teeth to provide the highest levels of hold. Best used in medium to soft ground. The flared design makes them highly resistant to bending but as with all plastic pegs, they can be damaged if hammered into an underground rock.