Hey guys! Ever wondered about all the bits and pieces that make up your trusty Starrett combination square? These tools are essential for any serious woodworker, metalworker, or DIY enthusiast. Understanding each component not only helps you maintain your square but also ensures you're using it to its full potential. Let's dive into the anatomy of a Starrett combination square and explore each part in detail. Knowing your tools inside and out is super important.

What is a Starrett Combination Square?

Before we get into the nitty-gritty of the parts, let's quickly recap what a Starrett combination square actually is. Simply put, it's a versatile measuring tool used for a variety of tasks, including marking, measuring, checking squareness, and finding angles. Starrett is a brand known for its precision and quality, making their combination squares a favorite among professionals. Combination squares are called that because they combine multiple tools into one, giving you a whole workshop's worth of measuring capability in a single, handy instrument. Its beauty lies in its modular design, with different heads that slide onto a precision-ruled blade. This design makes it incredibly adaptable to various tasks, from simple measurements to complex layouts. It is really important to choose a high quality one to ensure a higher level of accuracy and precision on your projects.

Key Components of a Starrett Combination Square

Okay, let’s break down each of the main parts. Knowing these will make you a Starrett Combination Square whiz in no time!

The Blade (or Rule)

The blade is the heart of the combination square. It’s a precision-graduated steel rule, typically available in various lengths (6", 12", 18", 24", etc.). The graduations are usually in inches and fractions thereof (like 1/8", 1/16", 1/32", and 1/64") on one side, and sometimes metric on the other. Accuracy is paramount here; Starrett blades are manufactured to very tight tolerances to ensure reliable measurements. Starrett blades are hardened and tempered for durability, meaning they can withstand a fair amount of use and abuse without losing their accuracy. Look for blades with etched or laser-marked graduations, as these tend to be more durable and easier to read than printed markings. The blade slides through the various heads and is secured by a locking mechanism, allowing you to adjust the distance and take precise measurements. Taking care of the blade is essential; keep it clean and lightly oiled to prevent rust and maintain its accuracy over the long haul. Remember, the blade is the foundation of all your measurements, so treat it with respect!. A high-quality blade ensures that all your measurements are accurate and reliable, preventing costly errors in your projects. It's truly the backbone of your combination square!

The Square Head (or Stock)

The square head is the most commonly used part of the combination square. It’s used to check and mark right angles (90 degrees) and also includes a 45-degree angle for miters. Typically, square heads are made from cast iron or hardened steel, precision-machined to ensure accuracy. A key feature of the square head is its hardened steel face, which provides a reliable reference surface. The head slides along the blade and can be locked in place with a thumbscrew or locking lever. High-quality square heads will have a snug fit with the blade, minimizing play and ensuring accurate readings. Some square heads also incorporate a spirit level (or bubble level) for verifying horizontal and vertical surfaces. This adds another layer of versatility to the tool, allowing you to use it for leveling tasks as well. When using the square head, always make sure the blade is fully seated and the locking mechanism is secure before taking any measurements or making any marks. This will prevent movement and ensure accurate results. The square head is your go-to for basic squareness checks and layout work, making it an indispensable part of the combination square set. Make sure to keep the reference surfaces clean and free from debris to maintain accuracy. A well-maintained square head will provide years of reliable service. It is important to remember to store it in a safe place away from any sources of possible damage. That is how you make your equipment last longer.

The Protractor Head

The protractor head is used for measuring and marking angles. It typically consists of a rotating turret with degree markings and a locking mechanism to secure the desired angle. Protractor heads are incredibly useful for laying out angles for woodworking projects, metal fabrication, and other applications where precision angles are required. High-quality protractor heads will have clear, easy-to-read markings and a smooth, precise rotation. The turret usually rotates 180 degrees in either direction, allowing you to measure angles from 0 to 180 degrees. Some protractor heads also include a vernier scale for even more precise angle measurements. The protractor head attaches to the blade in the same way as the square head, sliding along the blade and locking in place. When using the protractor head, make sure the blade is fully seated and the locking mechanism is tight to prevent any slippage. It is important to periodically check the accuracy of the protractor head using a known angle reference, such as a precision angle block. This will ensure that your angle measurements are accurate and reliable. The protractor head is a valuable addition to the combination square set, expanding its capabilities and making it a versatile tool for a wide range of projects. With a little practice, you'll be laying out angles like a pro in no time! It is important to keep it away from water to avoid corrosion.

The Center Finding Head

The center finding head is designed to quickly and accurately locate the center of round stock or other circular objects. This head typically consists of two arms that form a V-shape, with the blade running along the center of the V. Center finding heads are invaluable for machinists, metalworkers, and woodworkers who frequently need to find the center of cylindrical pieces. To use the center finding head, simply place the round stock between the two arms and slide the head until both arms make contact with the stock. The blade will then indicate the center point. High-quality center finding heads will be precision-machined to ensure accurate centering. The arms should be parallel and the V-angle should be precisely aligned with the blade. Some center finding heads also include a locking mechanism to hold the head in place while marking the center point. When using the center finding head, make sure the stock is clean and free from debris to ensure accurate results. It is also important to check the accuracy of the center finding head periodically using a known round stock. The center finding head is a specialized attachment that can save a significant amount of time and effort when working with round stock. It is a must-have for anyone who frequently needs to find the center of cylindrical objects. Remember to handle this part with care to avoid damage, as precision is key to its functionality. Keeping the arms clean and aligned will maintain its accuracy and extend its lifespan.

Common Issues and Maintenance

Like any precision tool, your Starrett combination square requires some TLC to keep it in top condition. Here are a few common issues and how to address them:

• Loose Heads: Over time, the locking mechanisms on the heads can become loose. Regularly check and tighten any screws or levers to ensure a snug fit. Using a small screwdriver or wrench, carefully tighten the screws or adjust the levers until the head locks securely onto the blade. Be careful not to overtighten, as this can damage the threads or the locking mechanism. If the screws are stripped or the levers are worn, consider replacing them with new parts. A loose head can lead to inaccurate measurements, so it's important to address this issue promptly. Keeping the threads clean and lightly lubricated can also help prevent them from binding or wearing out.
• Blade Rust: Steel blades are susceptible to rust, especially in humid environments. Wipe the blade down with a lightly oiled cloth after each use to prevent corrosion. Use a high-quality oil, such as mineral oil or gun oil, to protect the blade from moisture and oxidation. If rust does develop, use a fine steel wool or a rust eraser to gently remove it. Be careful not to scratch the blade or damage the graduations. After removing the rust, apply a fresh coat of oil to prevent it from returning. Storing the combination square in a dry place can also help prevent rust. Consider using a tool chest or a storage bag to protect it from moisture and dust.
• Inaccurate Readings: If you suspect your square is giving inaccurate readings, check the squareness of the head against a known square reference. Use a precision square or a granite surface plate to verify the accuracy of the combination square. If the head is not square, it may need to be adjusted or replaced. Some combination squares have adjustable heads that can be fine-tuned using a set screw or an eccentric cam. Consult the manufacturer's instructions for specific adjustment procedures. If the head is severely out of square, it may be necessary to replace it. Regular calibration and maintenance can help ensure that your combination square provides accurate readings for years to come. It is important to invest in high-quality reference tools to verify the accuracy of your measuring instruments.

Where to Buy Starrett Combination Square Parts

Need to replace a worn-out blade or a damaged head? No worries! You can find genuine Starrett replacement parts from several sources:

• Online Retailers: Websites like Amazon, eBay, and tool supply stores often carry a wide selection of Starrett parts.
• Local Tool Stores: Check with your local hardware or tool supply stores. They may have some parts in stock or can order them for you.
• Starrett Distributors: Starrett has a network of authorized distributors who can provide you with genuine parts and service.

Conclusion

So there you have it! A comprehensive look at the parts of a Starrett combination square. Understanding each component and how to maintain it will ensure that your tool lasts a lifetime and provides accurate results for all your projects. Now go forth and measure with confidence!