The Ultimate Guide To Slotted Screw Bit Sizes

Slotted screw bits, also known as flathead or flat-blade screwdrivers, are a type of screwdriver with a single horizontal indentation in the fastener head. They are designed to fit into the slot of a screw to tighten or loosen it. The most common sizes for flathead screwdrivers are 3.5mm for precision and controls work, 5.5mm for general purposes, and 6.5mm for larger screws. When choosing the right slotted screw bit, it is important to select one that fits snugly into the slot of the screw to ensure effectiveness and prevent damage.

Flat-head/slotted screwdrivers

Flat-head screwdrivers are also known as slotted screwdrivers because the flat tip of the driver fits snugly into the slot of a screw to tighten or loosen it. A slotted screw is one of the most common types of screw, including the equally common Phillips head and the less common square head.

Slotted screwdrivers work best when they fit appropriately into the slot of the screw. For example, a screw with a head that is 1/4-inch wide is not easily turned by a driver only half as wide. Likewise, the thickness of the slot on the screw head should also be matched by the thickness of the tool for the best results.

Flat-head screwdriver sizes range from mere millimetres up to bigger fractions of an inch. Two measurements are noted for each screwdriver: the length of the shaft and the width of the head. Examples of flat-head screwdriver sizes in inches include 3/32 by 1 1/2, 3/16 by 1 1/2, 1/8 by 4, 3/16 by 4, and 1/4 by 4. The first number represents the width of the driver head, while the second size indicates the shaft length. The longer the shaft, the farther the screwdriver can reach into tight spaces.

Flat-head screwdrivers are sold individually, but it is best to have a set to cover all your needs. A screwdriver set can consist of just flat-head screwdrivers or a combination of flat-head and Phillips-head varieties. In a set, you will get a good selection of drivers, including at least one with a short shaft, one with a long shaft, and several in between.

Standard slotted screwdrivers are measured in inches and fractions of inches. However, having a set of miniature tools measured in millimetres is handy for precision screws, such as those found on glasses, watches, and small electrical components.

Some slotted screwdriver bits have straight parallel sides (not tapered like most screwdrivers) for maximum surface contact with the screws. Measurements are width x thickness.

Screwdriver sets

Slotted screwdrivers, also known as flat-head screwdrivers, are the easiest to recognise due to their wedge-shaped end. They are the simplest and cheapest to make and are commonly found in antique furniture, vehicles and equipment.

When it comes to screwdriver sets, it is better to buy the sizes that you need most rather than a full set that later proves incomplete.

Chapman MFG offers a range of hard case sets that come with a handle, mini ratchet, extension, and a slotted screwdriver bit size chart. Their #5589 Ultimate Gunsmith Slotted + Star/Torx Screwdriver Set is a popular choice with 20 total reviews.

Amazon also offers a wide range of slotted screwdriver sets, including:

• The Klein Tools 85153K Slotted Screw-Holding Screwdriver Set, which features positive gripping action and has been bought by over 600 customers in the past month.
• The Amartisan 10-Piece Magnetic Screwdrivers Set, which includes 5 Phillips and 5 Slotted tips and has been bought by over 5,000 customers in the past month.
• The Klein Tools 32500 11-in-1 Screwdriver / Nut Driver Set, which includes 8 bits (Phillips, Slotted, Torx, Square) and a cushion grip handle, and has been bought by over 7,000 customers in the past month.
• The SK 6-Piece Slotted Screwdriver Set, which features a magnetic screwdriver set and SureGrip Handle.
• The Crescent 4 Pc. Slotted Dual Material Screwdriver Set, which has been bought by over 100 customers in the past month.
• The Wiha 26197 7 Piece Precision Slotted and Phillips Screwdriver Set, which has received 25 reviews.

Standard slotted screwdrivers

When selecting a standard slotted screwdriver, it is important to consider the size of the screw head and the depth of the slot. The screwdriver should fit snugly into the slot of the screw for the best results. The longer the shaft, the greater the ability of the screwdriver to reach into tight spaces. For example, in automotive work, screws are often placed far back in an engine block, requiring a longer shaft. On the other hand, if the screw is easily accessible, a shorter shaft can be used.

When purchasing standard slotted screwdrivers, it is recommended to buy the individual sizes needed rather than a full set, as the set may be missing some required sizes. Additionally, it is important to choose the correct screwdriver bit size to prevent stripped screws and damage to the screw head, bit, or work surface.

Miniature slotted screwdrivers

When buying a miniature slotted screwdriver set, it is important to consider the quality and craftsmanship. Look for screwdrivers with precision tips and comfortable, grippy handles. It is also beneficial to choose a set with corrosion-resistant shafts, as this will ensure durability and a long lifespan. Some sets also come with extra features, such as a storage bag or a magnetic wristband.

It is worth noting that miniature slotted screwdrivers are not suitable for high-torque applications and are not meant to be used with power tools. They are designed for precise tasks that require accuracy rather than force.

Screwdriver bit lengths

Screwdriver bits are typically available in 1”, 2”, 3”, 4”, 6”, and 12” lengths. The length of the screwdriver bit you need depends on the task at hand. For example, longer shafts are better for reaching screws in tight spaces, such as those in automotive work. On the other hand, stubby slotted screwdrivers with shafts of 1 1/2 are useful for close-up work.

Screwdriver bits with extended torsion zones are recommended for heavy-duty impact driving.

Frequently asked questions