Osculati AISI 316 Stainless Steel Hex Socket Countersunk Head Screws DIN 7991 / UNI 5933, M3–M6

ID 1402770

$ 15.14

1-2 weeks delivery time

Diameter, mm:

Length, mm:

Item:

5 pcs
10 pcs
25 pcs
50 pcs

Osculati DIN 7991 / UNI 5933 countersunk screws are manufactured from AISI 316 stainless steel and feature a flat countersunk head with an internal hexagonal socket drive. Their tapered head design allows flush installation in suitably prepared countersunk holes, while the metric machine thread is designed for fastening with compatible nuts or tapped holes. AISI 316 stainless steel provides corrosion resistance for suitable marine and outdoor applications. The range includes 17 dimensional configurations in M3, M4, M5 and M6 thread sizes, with lengths from 12 to 100 mm. Each variant is supplied in a box containing 5, 10, 25 or 50 screws, depending on the selected dimensions.

Description
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Osculati AISI 316 Stainless Steel Hex Socket Countersunk Head Screws DIN 7991 / UNI 5933

Osculati countersunk socket screws are manufactured from AISI 316 stainless steel and are listed according to DIN 7991 / UNI 5933. These machine screws feature a flat countersunk head with an internal hexagonal socket and a metric threaded shaft for fastening compatible marine fittings, equipment components and mechanical assemblies.

The flat countersunk head has a tapered underside designed to fit into a matching countersunk recess. When correctly installed, the screw head can sit flush with the surrounding mounting surface, providing a smooth finish without a protruding head.

The internal hexagonal socket allows the screw to be tightened or removed using a correctly sized Allen key or hex driver. Unlike conventional slotted or cross-recessed screws, this design uses a hexagonal drive recessed into the screw head.

The metric machine thread is designed for installation into compatible tapped holes or with matching nuts. These screws are not self-tapping and require an appropriate threaded connection.

AISI 316 stainless steel provides corrosion resistance for suitable marine, outdoor and general mechanical applications. The countersunk head makes these screws useful for installations where a flush mounting surface is required.

The range includes 17 dimensional configurations across four nominal thread sizes: M3, M4, M5 and M6. Available screw lengths range from 12 to 100 mm, depending on the selected diameter. Each version is identified by an individual Osculati part number and supplied in a specified box quantity.

Technical Specifications

Brand	Osculati
Product Type	Countersunk Socket Head Machine Screw
Standards	DIN 7991 / UNI 5933
Material	AISI 316 Stainless Steel
Head Type	Flat Countersunk Head
Drive Type	Internal Hexagonal Socket
Thread Type	Metric Machine Thread
Available Thread Sizes	M3, M4, M5, M6
Available Length Range	12–100 mm
Box Quantities	5, 10, 25, 50 pcs
Number of Variants	17
Dimensions Format	Nominal Thread Diameter × Screw Length

Features and Applications

Manufactured from AISI 316 stainless steel for corrosion resistance.
DIN 7991 / UNI 5933 countersunk socket screw design.
Flat countersunk head for flush installation in a suitable recess.
Internal hexagonal socket for installation using a matching Allen key or hex driver.
Metric machine threads for use with compatible nuts or tapped holes.
Suitable for fastening compatible marine fittings, panels, brackets and mechanical components.
Available in four thread diameters and 17 dimensional configurations.
Supplied in boxes containing 5 to 50 screws, depending on size.

Available Sizes and Part Numbers

Thread Size	Length	Box Quantity	Osculati Part No.
M3	12 mm	50 pcs	A4-7991-03X012
M3	20 mm	50 pcs	A4-7991-03X020
M3	30 mm	50 pcs	A4-7991-03X030
M4	16 mm	50 pcs	A4-7991-04X016
M4	20 mm	50 pcs	A4-7991-04X020
M4	30 mm	50 pcs	A4-7991-04X030
M4	40 mm	25 pcs	A4-7991-04X040
M4	50 mm	25 pcs	A4-7991-04X050
M5	20 mm	50 pcs	A4-7991-05X020
M5	40 mm	25 pcs	A4-7991-05X040
M5	50 mm	25 pcs	A4-7991-05X050
M6	20 mm	50 pcs	A4-7991-06X020
M6	30 mm	25 pcs	A4-7991-06X030
M6	40 mm	25 pcs	A4-7991-06X040
M6	60 mm	10 pcs	A4-7991-06X060
M6	70 mm	10 pcs	A4-7991-06X070
M6	100 mm	5 pcs	A4-7991-06X100

Size Selection

Select the required nominal metric thread diameter and screw length according to the thickness of the connected components and the available mounting space. Ensure that the countersunk recess accommodates the screw head and that the threaded connection provides suitable engagement.

Available lengths differ between thread diameters. Each dimensional configuration has a fixed box quantity as indicated above.