Description
BGS set screw assortment 91 pcs is an assortment of metric steel set screws to the DIN 913 standard. All the screws in the set have a flat point and an internal hexagon socket, so the screw sinks fully into the threaded hole and leaves no protruding head.
The set covers six sizes in the range M3–M8: M3 x 5 mm (4 pcs), M4 x 5 mm (20 pcs), M5 x 6 mm (15 pcs), M6 x 10 mm (30 pcs), M8 x 10 mm (10 pcs) and M8 x 12 mm (12 pcs). The quantities are weighted towards M4 and M6, the most common sizes in machine work.
A set screw locks a part on a shaft by pressing the flat end of the screw against the surface of the shaft. The flat point spreads the clamping force over a ring-shaped contact surface, so it does not leave the kind of dent in the shaft surface that a cone or cup point screw does. The flat point is therefore suitable for a cylindrical shaft from which the part is meant to be moved or removed later.
The hexagon socket lets you tighten the screw with a hex key even in a confined space. DIN 913 corresponds to ISO 4026, so the screws are dimensionally interchangeable with other set screws to the same standard. The assortment is supplied in a plastic compartment box with a transparent lid and its own compartment for each size.
Intended use and suitability:
A set screw is used to stop axial and rotational movement of a part on a shaft when the fixing must not extend beyond the outer surface of the part.
- Power transmission: locking pulleys, sprockets, gears and coupling halves on a shaft, often as extra security for a key.
- Electric motors and pumps: fixing fan impellers, rotor accessories and bushes fitted on pump shafts.
- Adjustment mechanisms: locking levers, cams, stops and positioning rings after adjustment.
- Tool holders and fixtures: positioning stops and guides in a jig or fixture.
- Maintenance: replacing a lost set screw or one with damaged threads in equipment repair without buying a separate size.
Package contents:
- M3 x 5 mm: 4 pcs
- M4 x 5 mm: 20 pcs
- M5 x 6 mm: 15 pcs
- M6 x 10 mm: 30 pcs
- M8 x 10 mm: 10 pcs
- M8 x 12 mm: 12 pcs
- Plastic compartment box with transparent lid
Features:
- Flat point: the ring-shaped contact surface spreads the clamping force and leaves a smaller dent in the shaft surface than a cone point.
- DIN 913 / ISO 4026: standard dimensions guarantee that the thread and hexagon socket are compatible with other parts to the same standard.
- Internal hexagon socket: the screw sinks fully into the hole, and a hex key reaches it for tightening even in a confined space.
- Six sizes M3–M8: the most common sizes for machine work in one box, with two lengths in size M8.
- Weighted quantities: most pieces in sizes M6 x 10 (30 pcs) and M4 x 5 (20 pcs), which are used up fastest in maintenance.
- Compartment box: the sizes stay apart and the transparent lid shows the contents without opening.
Technical specifications:
- Number of parts: 91 pcs.
- Sizes: 6.
- Threads: M3, M4, M5, M6, M8 (metric coarse thread).
- Lengths: 5, 6, 10 and 12 mm.
- Standard: DIN 913 (ISO 4026).
- Point type: flat point.
- Drive: internal hexagon socket.
- Hex keys: M3 = 1.5 mm, M4 = 2 mm, M5 = 2.5 mm, M6 = 3 mm, M8 = 4 mm.
- Material: steel.
BGS set screw assortment 91 pcs instructions for use:
Choosing the size: Measure the thread and length of the old screw, or determine the size of the threaded hole in the part with a thread gauge. Choose the length so that the screw sits flush with the surface of the threaded hole or slightly below it; a screw that is too long sticks out and one that is too short does not reach the shaft.
Fitting: Clean grease and dirt from the threaded hole and the contact point on the shaft. Place the part on the shaft in the correct position and screw the set screw into the hole by hand until it bottoms.
Tightening: Tighten the screw with a hex key of the correct size in a smooth movement. Use a short key or a torque wrench: with a long handle, it is easy to apply enough torque to a small hexagon socket to break it. When the fixing has two screws, tighten them alternately.
Securing: Where the part is exposed to vibration, use a threadlocker or two set screws on top of each other. Check the tightness after the first period of use and regularly after that.
Removal and maintenance: Clean chips out of the hexagon socket before inserting the key, so that the key goes all the way to the bottom. Replace the screw with a new one if the edges of the socket are rounded or the thread is damaged. Store the screws in their compartments in a dry box.
Warnings:
- Always use a hex key of the correct size. An undersized key rounds the edges of the socket, after which the screw can no longer be removed.
- Do not overtighten. Too much torque stretches the thread, breaks the screw or raises a bump on the shaft surface that prevents the part from being removed.
- Hardened steel is brittle: a breaking screw can throw fragments. Wear safety glasses when tightening and loosening.
- Do not reuse a screw with damaged threads or a rounded socket.
- The set contains small parts, which are a choking hazard. Store in a closed box out of the reach of children and pets.
- Steel screws rust in damp and corrosive conditions. For outdoor use, choose a corrosion-resistant screw.
Frequently asked questions (FAQ):
What sizes does the BGS set screw assortment 91 pcs contain? Six sizes: M3 x 5 (4 pcs), M4 x 5 (20 pcs), M5 x 6 (15 pcs), M6 x 10 (30 pcs), M8 x 10 (10 pcs) and M8 x 12 (12 pcs).
What is a DIN 913 set screw? A headless threaded pin to DIN 913 (ISO 4026) with a flat point and an internal hexagon socket.
When is a flat point better than a cone point? A flat point suits a cylindrical shaft when you want to be able to remove or move the part later: it does not dig a recess into the shaft surface. A cone point locks more tightly but marks the shaft permanently.
What size hex key do the set screws need? M3 needs a 1.5 mm, M4 a 2 mm, M5 a 2.5 mm, M6 a 3 mm and M8 a 4 mm hex key.
How do I stop a set screw loosening under vibration? Use a medium-strength threadlocker or fit two set screws on top of each other in the same hole; check the tightness after the first period of use.
Are the screws suitable for inch threads? No. All the screws in the set have metric coarse threads M3–M8.
Recycling instructions:
Set screws taken out of use are steel scrap and go to metal collection. The metal can be recycled without loss of quality.
The plastic compartment box goes to plastic collection when it is taken out of use. The shipping cardboard goes to cardboard collection.
