\documentclass{book}
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\RequirePackage{booktabs}

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\RequirePackage{graphicx,rotating,booktabs}
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\usepackage{capt-of}% or use the larger `caption` package
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\begin{document}
\newcommand{\minitab}[2][l]{\begin{tabular}{#1}#2\end{tabular}}
\captionof{table}{ ابعاد واشرهای سادۀ متریک (همۀ ابعاد به میلی‌متر)}
\vspace{-1mm}
\tiny
{\tabulinesep=1mm
\begin{tabular}{c|c|c|c|c|c|c|c|c|c|c|c|c|c|c|c|c}
\multicolumn{4}{r|}{\footnotesize\textbf{كاسه}}&
\multicolumn{4}{r|}{\footnotesize\textbf{مخروط}}&
\multicolumn{9}{c}{}\\
\specialrule{1.5pt}{1pt}{1pt}

\multicolumn{2}{c|}{\multirow{2}{*}{\minitab[c]{قطر\\ پلۀ\\  پشت‌گير}}}&\multicolumn{1}{c|}{\multirow{2}{*}{عرض}}&\multicolumn{1}{c|}{\multirow{2}{*}{\minitab[c]{شعاع\\ ماکزیمم \\ گُردۀ\\ پوسته}}}&\multicolumn{2}{c|}{\multirow{2}{*}{\minitab[c]{قطر \\پله‌های \\ پشت‌گير}}}&\multicolumn{1}{c|}{\multirow{2}{*}{عرض}}&\multicolumn{1}{c|}{\multirow{2}{*}{\minitab[c]{شعاع \\ماکزیمم \\ گُردۀ\\ شفت}}}&\multicolumn{2}{c|}{شمارۀ قطعه}&\multicolumn{1}{c|}{\multirow{2}{*}{\minitab[c]{مركز\\بار \\مؤثر}}} &\multicolumn{1}{c|}{\multirow{2}{*}{ضريب}}&\multicolumn{2}{c|}{\minitab[c]{\\بار نامی  در\\  $500\ \text{rpm}$ \\برای $L_{10}$ \\$=3000\ \text{h}$}}&\multicolumn{1}{c|}{\multirow{2}{*}{عرض}}&\multicolumn{1}{c|}{\multirow{2}{*}{\minitab[c]{قطر \\خارجی}}} &\multicolumn{1}{c}{\multirow{2}{*}{\minitab[c]{قطر \\ سوراخ}}}\\[4mm]\cline{9-10}\cline{13-14}

\multicolumn{2}{c|}{}&\multicolumn{1}{c|}{}&\multicolumn{1}{c|}{} & \multicolumn{2}{c|}{}&\multicolumn{1}{c|}{}&\multicolumn{1}{c|}{} & \multicolumn{1}{c|}{\multirow{2}{*}{\rl{كاسه}}}& \multicolumn{1}{c|}{\multirow{2}{*}{\rl{مخروط}}}&\multicolumn{1}{c|}{}&\multicolumn{1}{c|}{} & \multicolumn{1}{c|}{\minitab[c]{بار\\ محوری}}& \multicolumn{1}{c|}{\minitab[c]{تک\\‌رديفۀ \\شعاعی}}&\multicolumn{1}{c|}{}&\multicolumn{1}{c|}{}&\multicolumn{1}{c}{}\\[4mm]
\cline{1-2}\cline{5-6}

\rule{0pt}{1.2\normalbaselineskip}  $\mathbf{D_a}$  &$\mathbf{D_b}$&\multicolumn{1}{c|}{\textbf{C}}&\multicolumn{1}{c|}{$\mathbf{r}$} & $\mathbf{d_a}$ & $\mathbf{d_b}$ &\multicolumn{1}{c|}{\textbf{B}}&\multicolumn{1}{c|}{$\mathbf{R}$} & & &\multicolumn{1}{c|}{$\mathbf{a}$}&\multicolumn{1}{c|}{\textbf{K}} & \shortstack{\textbf{N} \\ \textbf{lbf}} & \shortstack{\textbf{N} \\ \textbf{lbf}} &\multicolumn{1}{c|}{\textbf{T}}&\multicolumn{1}{c|}{\textbf{D}}&\multicolumn{1}{c}{\textbf{d}}\\[.1mm]
\specialrule{1.5pt}{1pt}{1pt}

 & &  & & & & & & & & & & & & & & \\
 \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$^{\blacklozenge}\mathbf{30205}$\\ $$} & \shortstack{$^{\blacklozenge}\mathbf{30205}$\\ $$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} \\
 & &  & & & & & & & & & & & & & & \\
 \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$^{\blacklozenge}\mathbf{30205}$\\ $$} & \shortstack{$^{\blacklozenge}\mathbf{30205}$\\ $$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} & \shortstack{$\mathbf{48.5}$ \\ $1.91$} 
\end{tabular}}
\normalsize
\end{document}