SEMS combines two normally seperate parts-typically a screw and a washer- into one permanently pre-assembled cost saving component. Washers are hel in place under the screw head by the rolled threads; they will not fall off and are free to rotate.
Advantages:
* Speeds: production by eliminating hand assembly at the work station
* Permanent: Capturing of washer insures that it will never come off or be left off your assembly
* Adapts easily to automated feeding devices and driving tools
* Available in any combination of screw type, head style, washer and thread configuration
* Production Range: M2.5 (#2) ~ M 12 ~ (1/2". Length: 4mm (5/32") ~ 160mm (6")
* ISO 9001 certificated manufacturer & exporter
Screw And Washer Assemblies - SEMS, DIN6900
- Included in these specifications are SEMS comprised of the following types of screws and washers:
- Helical Spring Lock Washers
- Tooth Lock Washers
- Conical Spring Washers
- Plain Washers
- By the purchaser's drawing or standard
Screw and Washer Assemblies
Coarse threaded Screws with captive plain washer
DIN6900
Examples of screw and washer assemblies
|
|
Figure 1. Assembly with screw threaded approximately up to the head |
Figure 2. Assembly with screw unthreaded portion of shank |
Screw and Washer Assemblies
Coarse threaded Screws with captive curved spring lock washer
DIN6900
Examples of screw and washer assemblies
|
|
Figure 1. Assembly with screw threaded approximately up to the head |
Figure 2. Assembly with screw unthreaded portion of shank |
Screw and Washer Assemblies
Coarse threaded Screws with captive curved spring lock washer
DIN6900
Examples of screw and washer assemblies
|
|
Figure 1. Assembly with screw threaded approximately up to the head |
Figure 2. Assembly with screw unthreaded portion of shank |
Table 1. Dimensions
Thread Size (d) |
a |
/ 2" |
Washer Dimensions / DIN 6907 Washer |
Type C (7) |
h |
d2 |
Max |
Min |
~ |
|
M2.5 |
0.9 |
4 |
1.2 |
5.5 |
M3 |
1 |
4 |
1.2 |
6 |
(M3.5) |
1.2 |
6 |
1.5 |
7 |
M4 |
1.4 |
6 |
1.5 |
8 |
M5 |
1.6 |
6 |
1.8 |
9 |
M6 |
2 |
8 |
2.1 |
11 |
M8 |
2.5 |
10 |
2.4 |
14 |
M10 |
3 |
12 |
2.7 |
18 |
Use of the size give in brackets should be avoided where possible.
2 min is the smallest effective screw length manufacturable. |
| See relevant product standards for specifications for. |
Screw and Washer Assemblies
Coarse threaded Screws with captive curved spring lock washer
DIN6900
Examples of screw and washer assemblies
|
|
Figure 1. Assembly with screw threaded approximately up to the head |
Figure 2. Assembly with screw unthreaded portion of shank |
Table 1. Dimensions
Thread Size (d) |
a |
/ 2" |
Washer Dimensions / DIN 6907 Washer |
Type C (9) |
h |
d2 |
Max |
Min |
Max |
|
M2.5 |
0.9 |
4 |
0.72 |
6 |
M3 |
1 |
4 |
0.85 |
7 |
(M3.5) |
1.2 |
6 |
1.06 |
8 |
M4 |
1.4 |
6 |
1.3 |
9 |
M5 |
1.6 |
6 |
1.55 |
11 |
M6 |
2 |
8 |
2 |
14 |
M8 |
2.5 |
10 |
2.6 |
18 |
M10 |
3 |
12 |
3.2 |
23 |
M12 |
3.5 |
14 |
3.95 |
29 |
Use of the size give in brackets should be avoided where possible.
2 min is the smallest effective screw length manufacturable. |
See relevant product standards for specifications for. |
Tapping Screw and Washer Assemblies
DIN6901
Type C (with cone point)
Type F (with blunt end)
Table 1. Dimensions
|
|
Figure 1. Assembly with screw threaded approximately up to the head |
Figure 2. Assembly with screw unthreaded portion of shank |
Table 1. Dimensions
Thread Size |
/ 1" |
a |
Washer Dimensions / DIN 6903 Curved Spring Lock Washer |
Type A (1) |
Type B (2) |
Min |
Max |
h |
d2 |
h |
d2 |
ST2.9 |
5.5 |
1.1 |
1 |
7 |
1 |
9 |
ST3.5 |
8.5 |
1.3 |
1 |
8 |
1 |
11 |
(ST3.9) |
8.5 |
1.3 |
1 |
9 |
1 |
12 |
ST4.2 |
8.5 |
1.4 |
1 |
9 |
1 |
12 |
ST4.8 |
11.4 |
1.6 |
1 |
10 |
1.6 |
15 |
ST5.5 |
11.4 |
1.8 |
1.6 |
12 |
1.6 |
15 |
ST6.3 |
11.4 |
1.8 |
1.6 |
14 |
1.6 |
18 |
(ST8) |
14 |
2.1 |
1.6 |
16 |
2 |
24 |
2 min is the smallest effective screw length manufacturable.
Use of the size give in brackets should be avoided where possible. |
| 
