Reference number  
DRS 402: 2019  
© RSB 2019  
 
 
 RWANDA 
STANDARD  DRS 
412 
 
First e dition  
2019 -mm-dd 
 
Steel door frames  — Specification  
  DRS 412:  2019  
©RSB 2019 - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB2019  
All rights reserved. Unless  otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reproduce thi s document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
Tel. +250 788303492  
Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw  DRS 412 : 2019  
iii                ©RSB2019 - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 Requirements  ................................ ................................ ................................ ................................ .........  3 
4.1 Materials  ................................ ................................ ................................ ................................ .................  3 
4.2 Dimensions and Tolerances  ................................ ................................ ................................ .................  4 
4.2.1 Dimensions  ................................ ................................ ................................ ................................ ............  4 
4.2.2  Tolerances  ................................ ................................ ................................ ................................ ............  45 
4.2.3  Profiles  ................................ ................................ ................................ ................................ .................  45 
5 Construction  ................................ ................................ ................................ ................................ ..........  5 
6 Fittings  ................................ ................................ ................................ ................................ ....................  5 
6.1 Fixing lugs  ................................ ................................ ................................ ................................ ..............  5 
6.2 Hinges  ................................ ................................ ................................ ................................ .....................  6 
6.3 Lock strike plate  ................................ ................................ ................................ ................................ .... 7 
6.4 Shock absorbers  ................................ ................................ ................................ ................................ . 78 
7 Finish  ................................ ................................ ................................ ................................ ....................  89 
7.1 Pre-treatment  ................................ ................................ ................................ ................................ ....... 89 
7.2 Coatings  ................................ ................................ ................................ ................................ ...............  89 
7.3 Paintings  ................................ ................................ ................................ ................................ ................  9 
8 Workmanship  ................................ ................................ ................................ ................................ .........  9 
9 Storage and instal lation  ................................ ................................ ................................ ....................  910 
9.1 Storage  ................................ ................................ ................................ ................................ ...............  910 
9.2 Installation  ................................ ................................ ................................ ................................ ............  10 
10 Marking  ................................ ................................ ................................ ................................ .................  10 
Annex  A (informative)  Sampling of steel door frames  ................................ ................................ ............  1112 
Annex  B (informative)  Ordering information and notes on fixing  ................................ ..........................  1213 
 DRS 412:  2019  
©RSB 2019 - All rights reserved                  iv 
 Foreword  
Rwanda Standard s are prepared  by Technical Committees and approved by R wanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national standards.  Final Draft Rwanda S tandards 
adopted by Technical committ ees are ratified  by me mbers of RSB Board of Director s for publication and 
gazettment as Rwanda Standards.  
DRS 412 was prepared by Technical Committee RSB/TC 47, Steel, aluminium and related products . 
In the preparation of this standard, reference was made to the following standard s: 
1) SANS 1129:2008 , (Edition 1.4) Steel door frames  
2) IS 4351:2003 , Steel door frames — Specifications  
3) ZS 357: 1996 , Pressed Steel Door Frames —  Specification  
The assistance de rived from the above source is hereby acknowledged with thanks.  
Committee membership  
The following organizations were represented on the Technical Committee on Steel, aluminium and related 
products  (RSB/TC 47) in the preparation of this standard.  
GALFATOLES  
HEROCEAN LTD  
MANUMETAL LTD  
MOTA ENGIL  
RP IPRC NGOMA  
TKEA ENGINEERING  
University of Rwanda/College of Science and Technology (UR/CST)  
Rwanda  Standards Board  (RSB) – Secretariat  DRS 412: 2019  
1                ©RSB2019 - All rights reserved  
 Steel door frames  — Specification  
1 Scope  
This Committee Draft Rwanda  -Standard lays down requirements regarding material, dimensions construction  
and sampl ing of steel door  frames for internal and external use.   
2 Normative references  
The following documents are referred to in the text in such a way that some or all of  their content constitutes 
requirements of this document.  For dated references, only the edition  cited applies. For undated references, 
the latest edition of the reference d document (including any amendments) applies.  
RS ASTM A1008/A1008M: Standard Specification for Steel, Sheet, Cold -Rolled, Carbon, Structural, High -
Strength Low -Alloy, High -Strength Low -Alloy with Improved Formability, Solution Hardened, and Bake 
Hardenabl e 
ASTM A580 / A580M -18 Standard Specifications for Stainless Steel Wire  
RS ISO 4998 Continuous hot -dip zinc -coated and zinc -iron alloy -coated carbon steel sheet of structural quality  
RS ISO 1461 Hot dip galvanized coatings on fabricated iron and steel arti cles -- Specifications and test 
methods  
RS ISO 3574 Cold-reduced carbon steel sheet of commercial and drawing qualities  
RS ISO 3575 Continuous hot -dip zinc -coated and zinc -iron alloy -coated carbon steel sheet of commercial and 
drawing qualities  
ISO 12944 -5 Paints and varnishes -- Corrosion protection of steel structures by protective paint systems -- 
Part 5: Protective paint systems  
RS EAS 11 Galvanised plain and corrugated steel sheets — Specification  
RS EAS 134 Cold rolled steel sections — Specification  
3 Terms and definitions  
For the purposes of this standard, the follow ing terms and definitions apply . 
3.1 
door frame  
frame in which door leaf is hung   
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 3.2 
door leaf  
single, independently moving panel of a door. The single -leaf door  is the most common variety of doors . It 
features a single panel that fills an entire  doorway  space. Double -leaf doors , also known as French  doors , 
have two panels that each open outward.  
3.3 
lot 
not less than 10 and not more than 150 assembled door frames of the same type, materials , dimensions, 
construction, and (when relevant) handing, from one manufacturer, submitted at any one time for inspection  
3.4 
modular sizes  
standard size as specified for example in Figure 1  
3.5 
profile  
generic term used to describe the cross section shape of the frame  
3.6 
rebate  
deep groove that is cut into the edge of a door frame to allow a tighter fi t 
Note: single rebate frame is a frame that has one of these grooves, and a dual rebate frame is a frame that 
has more than one. Dual r ebate frames are much  thicker (for example 50% thicker for composite doors) and 
offer the owner more security . 
3.7 
jamb  
vertical steel door frame to which a door is hinged  
3.8 
transom  
horizontal crossbar across the top of a door frame  
Note: A transom is usually a decorative gla ss window at the top of the door.  DRS 412: 2019  
3                ©RSB2019 - All rights reserved  
 3.9 
slip-on drywall frame  
term describing a 3 -sided frame designed to be installed after the wall is erected and finished  
3.10 
grout 
mixture of water, cement, and sand which is used to fill gaps or used as reinforcement in  existing structures  
3.11 
mortar  
mixture of sand, water, and cement or li me that is used to fix bricks,  stones  to each other when building walls  
or to fix a door frame to walls  
Note: Grout differs from mortar in the quantity of cement and aggregates such as sand, stones, etc.. Refer to 
clauses 6.3 and 9.2.  
3.12 
sill 
part of the door frame which runs along the bottom and sits directly on the floor foundation  
Note: Sill is also known as threshold  
4 Requirements  
4.1 Materials  
Steel door frames shall be manufacture d from the materials conforming to at least one of the following 
standards given in Table 1. If steel other than specified above is used, it shall be agreed upon between the 
purchaser and the manufacturer  
Table 1 — Material for door frames  
 
S/N Material  Reference  
1 Mild steel sheet (cold rolled)  
 RS ISO 3574 or ASTM A1008 / 
A1008M  
 
2 Galvanized steel sheets — Plain grade — 
Lock forming (GPL), Zinc coating 120 g/m2 
inclusive of both sides  
 RS EAS 11 or RS ISO 3575  
  
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4.2 Dimensions and Tolerances  
4.2.1  Dimensions  
4.3.1.1 The overall sizes and types of the door frames shall generally conform to the modular sizes as shown 
in Figure 1. However, sizes, types, other than those shown in Figure 1 as agreed to between the manufacturer 
and the purchaser are also permitted.  
4.3.1.2 The sizes shown in Figure 1 are overall heights and widths to the outside of steel door frame. These sizes are 
derived after allowing a 5mm clearance on all four sides for the purpose of fitting the frame into modular openings.
Figure 1 — Size of steel door frames  
 
4.2.2  Tolerances  
The sizes indicated in Figure 1 for steel door frames shall not vary by more than ± 2mm.  
4.2.3  Profiles  
Steel door frames profile (either single rebate or double rebate) shape, size, physical properties and 
tolerances shall  be in accordance with the provision of RS EAS 134. It shall not be less than 1.2mm nominal 
thickness  
DRS 412: 2019  
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 5 Construction  
5.1 Each door frame shall consist of hinge jamb, lock jamb and head, the whole of which shall be welded 
together or rigidly fixed by mechani cal means. Two base ties shall be applied to the frame as shown in Figure 
2. 
 
5.2 The base ties of internal frames shall be braced with adjustable  or rigidly fixed  base ties to hold the frames 
rigid during transit and erection. The base ties may be fitted to suit the thickness of floor finish which should be 
stated when ordering.  
 
 
Figure 2 — adjustable  base ties  
6 Fittings  
6.1 Fixing lugs  
6.1.1. There shall be three adjustable lugs for each jamb to fix the door frame into the drywall. Additional fixing 
may be required by the Manufacturer or Engineer. The fixing lug shall be composed of the head and tail as 
shown on Figure 3. 
 
Figure 3 — fixing  lugs dimensions  
 
6.1.2. The head shall be made from flat steel strip 25mm wide and having nominal thickness of 1.25mm  
 
 
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 6.1.3 The tail of the lugs shall be 200mm long and shall be made of steel strip not less than 40mm wide and 
having nominal thickness of 1.25mm.  
 
6.2 Hinges  
6.2.1 General  
Hinges shall be made of mild steel sheet not less than 2.5mm nominal thickness. They shal l have five 
knuckles and shall be fitted with a removable pin of minimum diameter 6mm. The leaves, pin and screws 
(where used) shall be zinc coated after manufacture, the method to be at the manufacturer’s discretion. The 
leaves for screwing to the door sh all have four countersunk holes . 
6.2.2 Number of hinges required  
Two (2) hinges shall be used for a 1.52m height steel door frame. One (1) additional hinge shall be used for 
each 0.52m additional height as shown in Figure 4. 
Note: For a door frame of 2.04m  (it has an additional 0.52m height which means 1.52m+0.52m), therefore, 
this door frame shall have three hinges.  
 
Figure 4 — Hinge(s) location on a steel door frame  
6.2.3 Hinge fixings  
Hinges shall be welded or screwed to the frame at the purchaser’s dis cretion. The outer surface of the hinge 
leaf fitted to the frame shall not project above the surface of the rebate. Where screwed on hinges are used, 
there shall be a reinforcing plate fixed to the frame to which the hinge shall be screwed. The plate shall  be of 
mild steel sheet not less than 2.5mm nominal thickness. The length of the plates shall not be less than 70mm 
greater than the length of the hinge. The edge of the holes shall be not less than the diameter of the hole from 
the edge of the plate.  
DRS 412: 2019  
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 6.3 Lock  strike plate  
Provision shall be made to fix lock strike plates of door locks or latches, a slot suitable for lock strike plate 
shall be pierced into the rebate of the frame and necessary fixing arrangement shall be provided as shown on 
Figure 5.  
Note: The re are different types of door locks (keyless entry system, mortise lock, etc.) and latches (night latch, 
etc.).  
 
Figure  5 — Side hung door frame  
6.4 Shock absorbers  
For side -hung door, there sh ould be not less than three buffers of rubber or other suitable material inserted in 
holes in the rebate in that case  one shall be located at the centre of the lock jamb of frame and other two shall 
be 300mm from top and bottom of the frame as shown in Figure 4. For double leaf doors, two buffers shall be 
provided as shown in Figure  6. 
 
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Figure 6 — Shock absorber for double leaf door frame  
7 Finish  
7.1 Pre-treatment  
Methods to pre -treat the surface of the door frames, prior to painting or coating, shall be selected as per ISO 
8504 -1 to provide a cleaned surface free from rust, dirt, grease, oil, loose scale, weld spatter and any other 
foreign matter. Any other mechanical means such as sand and shot blasting or chemical means that can 
provide same degree of cleanlines s may be applied.  
7.2 Coatings  
7.2.1 Galvanized coatings   
7.2.1.1 Galvanized coatings on door frames and fittings made from pre -galvanized sheet shall comply with the 
coating requirement Z275 as referred to in ISO 4998.  
7.2.1.2 Galvanized coatings on door fra mes and fittings (other than hinges) that are galvanized after 
manufacture shall comply with the relevant requirements of ISO 1461 .  
7.2.1.3 Galvanized coatings on hinges shall have been applied by hot -dipping or by another acceptable 
method, but in all ca ses the thickness of the coating shall be at least equal to the relevant value specified in 
ISO 1461 .  
7.2.1.4 Any small area of a galvanized coating that is impaired during welding or damaged in any other way 
shall be recoated with a zinc -rich epoxy -based  primer.  
7.2.2 Sprayed coatings  
A sprayed zinc or aluminium coating shall comply with the relevant requirements of ISO 2063 -1 and shall have 
a local thickness of at least 75 μm to all surfaces, including interior non -visible surfaces.  
DRS 412: 2019  
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 7.3 Paintings  
7.3.1  All surfaces of the door frame , including interior non -visible surfaces,  shall receive a factory prime coat 
complying with the provision of ISO 12944 -5. 
 
7.3.2  When specified, top coat and intermediate coats should be on all surfaces of the door frame exp osed to 
view as part of paint finishing as per ISO 12944 -5. 
 
7.3.3  If door frames are not factory finish painted, a compatible coat of finish paint shall be applied in the field. 
The finish paint shall be of a type recommended for use on prime -painted stee l. Consult the door and frame 
manufacturer’s literature for description of primer used. The manufacturer of the finish paint should verify 
compatibility with the primer.  
 
 
 
8 Workmanship  
8.1 Door frames shall be free from:  
a) dents  
b) bends in the metal  
c) Any other  damage or defect (including scratches, chips, and runs in the coatings) that would impair their 
function, or serviceability or both.  
8.2 The rebates of head members and transoms shall be correctly aligned with those of the jambs.  
 
9 Storage and installation  
9.1 Storage  
8.1.1  Frames shall be stored vertically under cover. The units shall be placed on at least 102  mm high wood 
sills or in a manner that will prevent rust or damage.  
8.1.2  The use of non -vented plastic or canvas shelters that can create a humidity ch amber shall be avoided. A 
6.3mm space between the door frames shall be provided with timber or similar blocking to promote air 
circulation.  
8.1.3  Proper jobsite storage is extremely important in maintaining the quality and integrity of the factory 
applied paint.  
8.1.4  Improper storage of material will have an adverse effect on the factory applied paint’s ability to meet the 
requirements/criteria in Annex A.   
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 9.2 Installation  
8.2.1  All frames, other than drywall slip -on types, shall be fastened to the adjacent s tructure so as to retain 
their position and stability. Slip -on drywall frames shall be installed in prepared wall openings in accordance 
with manufacturer’s instructions  
8.2.2  Where grouting is required in masonry installations, frames shall be braced or f astened in such a way 
that will prevent the pressure of the grout from deforming the frame members. Grout shall be mixed to provide 
a 101.6mm maximum slump consistency and hand trowelled into place. Grout mixed to a thinner, “pumpable” 
consistency shall no t be used. Excess water from thin consistency grout will cause premature rusting of steel 
frames and probable deformation or discoloration of certain wall constructions.  
8.2.3  Steel frames, including fire rated -frames do not require grouting. Grouting shal l not be used for frames 
installed in drywall walls.  
 
10 Sampl ing 
Sampling shall be done as per Annex A.  
11 Marking  
Each door shall be marked , in a non -permanently visible but accessible location,  with the following:  
a) The manufacturer's name or trade mark;  
b) Any fire rating or other critical door performance information;  
c) The certification mark of the standards body or certification body, if used.  
  DRS 412: 2019  
11                ©RSB2019 - All rights reserved  
 Annex  A 
(normative)  
 
Sampling of steel door frames  
A.1 Scale of sampling  
A.1.1  Lot in any consignment all the frames of the same size, designation, profile and manufactured under 
similar conditions of production shall be grouped together to constitute a lot.  
A.1.2  Samples shall be selected and tested from each lot separately to determine its conformity or otherwise 
to the requi rements of the standard.  
A.1.3  The number of frames to be selected at random from a lot for inspection and testing shall depend upon 
the size of the lot and shall be in accordance with Table 1. 
A.1.4 All frames selected in the sample shall be inspected for  material (see 4.1), dimensions and tolerances 
(see 4.2), construction (see 5), fittings (see 6) finish  (see 7) and marking (see 11)  
Table 1 Sample size and permissible number of defective  
S/N Lot size  Sample size  Permissible number of 
defectives  
1 1-15 3 0 
2 16-25 5 0 
3 26-50 8 0 
4 51-100 13 1 
5 101-150 20 2 
6 151-300 32 3 
7 301-500 50 5 
8 Up to 500  80 7 
 
A.2 Criteria for conformity  
A frame which is found not meeting any one or more of these requirements inspected for (see A.1.5)  shall be 
considered as defective  
  
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 Annex  B 
(informative)  
 
Ordering information and notes on fixing  
B.1 When ordering a steel door frame, the purchaser should specify the following:  
a) Handling of the door frame  
b) Details of the profile  
c) Dimensions of the door frame  
d) Hinges type whether screwed or welded  
e) Delivery conditions  
B.2 The following instructions should be followed when fixing the door frames  
f) Place the flame in position, ensuring that the base tie is set at correct height for appropriate finished floor 
level,  
g) Plumb to ensure the flame is upright square and free from twist,  
h) Fix temporary struts between the jambs to prevent them from bulging inwards due to the weight of the wall 
or partition,  
i) Care should be taken not to distort the frame during construction,  
j) Build the walls up each side at equal height,  
k) Voids in back of frames should be filled in solid with mortar as the work proceeds,  
l) The three lugs provided to each side should be spaced not more than 750mm apart,  
m) Base ties should be removed after masonry has s et and before finished floor is laid,  
In instances where steel door frames are erected in pre -formed openings, or similar conditions resulting in a 
clearance between the joint face of the frame and the joint face of the wall partition, the clearance may b e 
made up to suit the designer, with a filler piece architrave or other design solution.  DRS 412: 2019  
13                ©RSB2019 - All rights reserved  
 Bibliography  
[1] ANSI/ SDI A250.10, Test Procedure and Acceptance Criteria for Prime Painted Steel Surfaces for Steel 
Doors and Frames  
[2] Test Procedure and Acceptanc e Criteria for Prime Painted Steel Surfaces for Steel Doors and Frames or 
ANSI/SDI A250.3  
[3] BS EN 1245 -1975 Standard (Pdf file): Specification for Metal door frames (steel)  
[4] BS 1449 -1.1:1991 Steel plate, sheet and strip. Carbon and carbon -manganese pl ate, sheet and strip. 
General specification  
[5] Specifications for Standard Steel Doors and Frames (SDI -100) or ANSI/SDI A250.8 -2017  
[6]   Methods  for random sampling  
 
 DRS 402: 2019  
ICS 91.060.50  
 
 
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