Postal Exam 955 Details

Postal Exam 955 is an extremely challenging test. Failure rates can exceed 95%. The technical portion of the exam consists of two sections: the Multicraft section and the Spatial Relations section.

Multicraft Section

According to the Postal Service, the Multicraft section (the technical part of the test) covers the following 21 major topics and 131 subtopics. This section consists of 60 multiple choice questions. Note, however, that there are far more than 60 technical topics listed below. How can they cover all those topics with only 60 questions? They cannot and do not. There are numerous versions of exam 955. Each version has different questions, and no version covers all the topics. Since you do not know exactly which version to expect or exactly which topics will be included when you take the exam, you must be prepared to answer questions about all the topics.

Basic AC/DC Theory
Capacitance
Current Calculation
Inductance
Ohms Law
RC Networks
Resistance Calculation
Simple Circuits

Combustion
Analyzers
Control Systems
Furnaces, Boilers & Heating Systems

Computer & PLC
Addressing
Input/Output
Keyboard
Registers
Symbols

Controls
AC
DC
Devices

Digital Electronics
Adders
And/or
Counters
Exclusive/or
Nand/nor
Shift Registers

Electrical Maintenance
Failure Analysis
Prevention
Troubleshooting

Hydraulics
Control Valves
Filters
Fluids
Hydraulic Actuators
Piping & Sealing
Pressure Regulation
Pumps
Servo Valves

Power Distribution
Fuses
Kilovars
Kilowatts
Metering
Oil & Air Circuit Breakers
Overload
Overvoltage
Phase Loss Relays
Transformers
Voltage Loss

Power Supply
Basic Transformer Theory
Filtering
Gating
Rectifiers
SCRs
Zener Diode

Power Transmission
Alignment
Bearings
Belt Drives
Brakes
Cables & Sheaves
Chains & Sprockets
Clutches, Cams & Couplings
Gears
Motors
Speed Changers / Reducers

Pumps
Alignment
Centrifugal
Horizontal
Positive Displacement
Seals
Thrust
Vertical

Lubrication
Dry Lubricants
Grease
Oils
Principles

Mechanical Maintenance
Bulk Storage
Prevention
Recording
Troubleshooting

Motors
AC
Control
DC
Generator
Maintenance

Piping
Accessories
Heat Exchanger
Metallic
Non-metallic
Specialized Valves
Steam
Strainers, Filters & Traps
Tubing, Hoses & Fittings

Pneumatics
Air Compressors
Air Dryers
Air Lubricators
Air Motors
Air Supply Systems
Cylinders
Regulation & Control
System Maintenance
Valves

Rigging
Cranes & Hoists
Fiber Rope & Knots
Levers, Jacks & Screws
Scaffolds & Ladders
Wire Rope & Chains

Schematics & Print Reading
Assembly Drawings
Electrical Symbols
Mechanical Drawing
Relay Logic
Schematics – Basic
Schematics – Complex Piping
Schematics – Complex Welding
Solid State Logic

Shop Machines, Tools & Equipment
Breaks
Drill Press
Flame Tools
Grinder
Pipe Cutting & Threading Machines
Pneumatic Tools
Presses
Saws

Test Instruments
Ammeter
Basic Analyzer (VOM)
Brush Recorder
High Voltage Test Equipment
Megger
Oscilloscope
Voltmeter

Welding
Air-arcing
Arc Welding
Brazing & Gas Welding
Cutting Torch
Electrodes

Spatial Relations Section

The Spatial Relations section is broken down into two segments – Matching Parts & Figures and Spatial Visualization. This section of exam 955 is an aptitude test, not a knowledge test. It tests your inherent ability to visualize how parts and pieces come together to form the “big picture” – to visualize the end product represented by a drawing or schematic, to visualize the assembly of a piece of equipment using illustrated instructions, etc. Spatial ability is essential for success in a job that deals with mechanics and maintenance, so the Postal Service views the Spatial Relations test as an important tool when recruiting for the jobs filled from exam 955. We will discuss the two segments of the Spatial Relations section individually below.

Matching Parts & Figures Segment

In the Matching Parts & Figures segment, you are to visualize what shape would result from fitting two or more 2D flat pieces together. Each question gives you drawings of two or more 2D flat pieces. For answer choices, you are given drawings of four larger shapes, each consisting of multiple pieces. Your job is to figure out which of these four options shows how the original two or more pieces can be fitted together without gaps or overlapping. You will usually have to turn the original pieces around, over, etc. in your mind in order to see how they might fit together to form one of the answer options. The below sample question may help you understand better.

Which of the following shapes (A, B, C or D) can be created by fitting these three pieces together?

This sample question gives us three triangles. Looking at the answer options, do any of them seem to include all three of our triangles fitted perfectly together? Option A has three triangles, but they are definitely not shaped like our original ones. Option C cannot be right because it has two triangles and a rectangle. Option D has three triangles, but two of them do not look like our originals. If you turn one of our original triangles upside-down, Option B looks like all three of our original triangles fitted perfectly together. That is our answer: Option B.

Spatial Visualization Segment

In the Spatial Visualization segment, each question gives you the top-, front-, and right-side views of an object. Then you are given four figures (A, B, C & D), one of which is the object represented by the original three views. You are to choose which of the four objects is indeed the one represented by the original three views. See the below sample for a better understanding.

The correct answer is C. Option C is the only one that fits our three original views.

Summary

When you take this exam, even though you only took one test, you get multiple scores. There is one score for each technical job filled from exam 955, each score is different, and it is possible that some of scores will be great while others are terrible.

Different jobs call for different skills. For instance, an Electronic Technician is expected to have more expertise in electronics than heating systems, and just the opposite is true for a Building Equipment Mechanic. There is a different scoring formula for each job, and the different formulas are weighted to place more emphasis on the skills needed for that particular job. So, the Electronic Technician formula places more emphasis on electronic questions, the Building Equipment Mechanic formula emphasizes heating system questions more, and so on.

Do you have the background necessary to succeed on this test? Nobody can answer that but you. This decision should be based upon your knowledge and experience in the technical fields covered on the exam. To succeed, you must have extensive technical education, training, and/or experience.